diff --git a/examples/reliability/concept_drift_time_series.py b/examples/reliability/concept_drift_time_series.py
new file mode 100644
index 0000000..07ddbf0
--- /dev/null
+++ b/examples/reliability/concept_drift_time_series.py
@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+# Copyright 2021 Huawei Technologies Co., Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+Concept drift example.
+Download dataset from: https://www.kaggle.com/camnugent/sandp500.
+File structure:
+    --archive
+        --individual_stocks_5yr
+            --__MACOSX
+            --individual_stocks_5yr
+        --all_stocks_5yr.csv
+        --getSandP.py
+        --merge.sh
+Please use the data in archive/individual_stocks_5yr/individual_stocks_5yr/XX.csv.
+In each csv file, there are 'date','open','high','low','close','volume','Name' columns.
+Please choose one column or multiple columns.
+'date' and 'Name' are non-data column, please do not use.
+"""
+
+import numpy as np
+from mindarmour import ConceptDriftCheckTimeSeries
+
+
+# input data
+DATA_FILE = r'archive/individual_stocks_5yr/individual_stocks_5yr/AEE_data.csv'
+data = np.loadtxt(DATA_FILE, str, delimiter=",")
+data = data[1:, 2].astype('float64')  # choose one column or multiple columns data[1:, 2:5]
+# Initialization
+concept = ConceptDriftCheckTimeSeries(window_size=100, rolling_window=10,
+                                      step=10, threshold_index=1.5, need_label=False)
+# drift check
+drift_score, threshold, concept_drift_location = concept.concept_check(data)
diff --git a/mindarmour/__init__.py b/mindarmour/__init__.py
index 9611107..a6ee59e 100644
--- a/mindarmour/__init__.py
+++ b/mindarmour/__init__.py
@@ -13,6 +13,7 @@ from .privacy.sup_privacy.sup_ctrl.conctrl import SuppressCtrl
 from .privacy.sup_privacy.train.model import SuppressModel
 from .privacy.sup_privacy.mask_monitor.masker import SuppressMasker
 from .privacy.evaluation.inversion_attack import ImageInversionAttack
+from .reliability.concept_drift.concept_drift_check_time_series import ConceptDriftCheckTimeSeries
 
 __all__ = ['Attack',
            'BlackModel',
@@ -24,4 +25,5 @@ __all__ = ['Attack',
            'SuppressModel',
            'SuppressCtrl',
            'SuppressMasker',
-           'ImageInversionAttack']
+           'ImageInversionAttack',
+           'ConceptDriftCheckTimeSeries']
diff --git a/mindarmour/reliability/__init__.py b/mindarmour/reliability/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/mindarmour/reliability/concept_drift/README.md b/mindarmour/reliability/concept_drift/README.md
new file mode 100644
index 0000000..70d118f
--- /dev/null
+++ b/mindarmour/reliability/concept_drift/README.md
@@ -0,0 +1,92 @@
+# Content
+
+## Concept drift Description
+
+In predictive analytics and machine learning, the concept drift means that the statistical properties of the target variable, which the model is trying to predict, change over time in unforeseen ways. This causes problems because the predictions become less accurate as time passes. Usually, concept drift is described as the change of data distribution over time.
+
+## Method
+
+### Model Architecture
+
+The concept drift detection method is based on the ESN (Echo state network). ESN is a type of reservoir computer that uses a recurrent neural network with a sparsely connected hidden layer (with typically 1% connectivity). The connectivity and weights of hidden neurons are fixed and randomly assigned.
+For time series concept drift detection
+
+### Detector
+
+For a time series, we select two adjacent time window and compare the features of the two window data to determine whether concept drift has occurred. For feature extraction, we choose to use the ESN network. The input of the ESN network is a certain window data, and the output is also the window data (like an auto-encoder). In this way, the ESN network is equivalent to a feature extractor. Features are represented by model parameters (weights and bias) of the ESN network. Finally, by comparing the difference of model parameters, we can determine whether the data has concept drift. It should be noted that the two windows are constantly sliding forward.
+
+## Dataset
+
+Download dataset https://www.kaggle.com/camnugent/sandp500.
+
+```bash
+├── archive
+  ├── all_stocks_5yr.csv
+  ├── getSandP.py
+  ├── merge.sh
+  ├── individual_stocks_5yr
+        ├──__MACOSX
+        ├──individual_stocks_5yr
+```
+
+Please use the data in archive/individual_stocks_5yr/individual_stocks_5yr/XX.csv.  
+In each csv file, there are 'date','open','high','low','close','volume','Name' columns, please choose one column to begin your code. 'date' and 'Name' are non-data column.  
+
+## Environment Requirements
+
+- Hardware(CPU/Ascend/GPU)
+    - Prepare hardware environment with CPU, Ascend or GPU processor.
+- Framework
+    - MindSpore
+- For more information, please check the resources below：
+    - MindSpore Tutorials
+    - MindSpore Python API
+
+## Quick Start
+
+### Initialization
+
+```python
+from mindarmour.reliability.concept_drift.concept_drift_check_time_series import ConceptDriftCheckTimeSeries
+
+concept = ConceptDriftCheckTimeSeries(window_size=100, rolling_window=10, step=10, threshold_index=1.5,
+                                      need_label=False)
+```
+
+>window_size(int): Size of a concept window, belongs to [10, 1/3*len(input data)]. If the data is periodic, usually window_size equals 2-5 periods, such as, for monthly/weekly data, the data volume of 30/7 days is a period. Default: 100.  
+rolling_window(int): Smoothing window size, belongs to [1, window_size]. Default:10.  
+step(int): The jump length of the sliding window, belongs to [1,window_size]. Default:10.  
+threshold_index(float): The threshold index, (-∞,+∞), Default: 1.5.  
+need_label(bool）: False or True. If need_label=True, concept drift labels are needed. Default: False.  
+
+### Data
+
+```python
+import numpy as np
+file = r'archive/individual_stocks_5yr/individual_stocks_5yr/AAP_data.csv'
+data = np.loadtxt(file, str, delimiter=",")
+data = data[1:, 2].astype('float64')  # here we choose one column or multiple columns data[1:, 2:5].
+```
+
+>data(numpy.ndarray): Input data. The shape of data could be (n,1) or (n,m).
+
+### Drift check
+
+```python
+drift_score, threshold, concept_drift_location = concept.concept_check(data)
+```
+
+>drift_score(numpy.ndarray): The concept drift score of the example series.  
+threshold(float): The threshold to judge concept drift.  
+concept_drift_location(list): The location of the concept drift.
+
+## Script Description
+
+```python
+├── mindarmour
+  ├── reliability     # descriptions about GhostNet   # shell script for evaluation with CPU, GPU or Ascend
+    ├──concept_drift
+        ├──concept_drift.py
+        ├──readme.md
+```
+
diff --git a/mindarmour/reliability/concept_drift/__init__.py b/mindarmour/reliability/concept_drift/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/mindarmour/reliability/concept_drift/concept_drift_check_time_series.py b/mindarmour/reliability/concept_drift/concept_drift_check_time_series.py
new file mode 100644
index 0000000..7e6b2db
--- /dev/null
+++ b/mindarmour/reliability/concept_drift/concept_drift_check_time_series.py
@@ -0,0 +1,404 @@
+# -*- coding: utf-8 -*-
+# Copyright 2021 Huawei Technologies Co., Ltd
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+"""
+Concpt drift module
+"""
+
+from itertools import groupby
+import numpy as np
+import matplotlib.pyplot as plt
+from mindarmour.utils._check_param import _check_array_not_empty
+from mindarmour.utils._check_param import check_param_type, check_param_in_range
+
+
+class ConceptDriftCheckTimeSeries:
+    """
+    Concept is used for example series distribution change detection.
+
+    Args:
+        window_size(int): Size of a concept window, belongs to [10, 1/3*len(input data)].
+            If the data is periodic, usually window_size equals 2-5 periods, such as,
+            for monthly/weekly data, the data volume of 30/7 days is a period. Default: 100.
+        rolling_window(int): Smoothing window size, belongs to [1, window_size]. Default:10.
+        step(int): The jump length of the sliding window, belongs to [1, window_size]. Default:10.
+        threshold_index(float): The threshold index, (-∞, +∞), Default: 1.5.
+        need_label(bool): False or True. If need_label=True, concept drift labels are needed.
+            Default: False.
+
+    Examples:
+        >>> concept = ConceptDriftCheckTimeSeries(window_size=100, rolling_window=10,
+        >>>                   step=10, threshold_index=1.5, need_label=False)
+        >>> data_example = np.array([np.random.rand(1000),
+        >>>                          np.random.rand(1000),np.random.rand(1000)]).T
+        >>> score, threshold, concept_drift_location = concept.concept_check(data_example)
+    """
+
+    def __init__(self, window_size=100, rolling_window=10,
+                 step=10, threshold_index=1.5, need_label=False):
+        self.window_size = check_param_type('window_size', window_size, int)
+        self.rolling_window = check_param_type('rolling_window', rolling_window, int)
+        self.rolling_window = check_param_in_range('rolling_window',
+                                                   rolling_window, 1, window_size)
+        self.step = check_param_type('step', step, int)
+        self.step = check_param_in_range('step', step, 1, window_size)
+        self.threshold_index = check_param_type('threshold_index', threshold_index, float)
+        self.need_label = check_param_type('need_label', need_label, bool)
+        self._in_size = window_size
+        self._out_size = window_size
+        self._res_size = int(0.1*window_size)
+
+    def _reservoir_model_feature(self, window_data):
+        """
+        Extract example features in reservoir model.
+
+        Args:
+            window_data(numpy.ndarray): The input data (in one window).
+
+        Returns:
+            w_out(numpy.ndarray): The output weight of reservoir model.
+            x_state(numpy.ndarray): The state of the reservoir model in the latent space.
+
+        Examples:
+            >>> input_data = np.random.rand(100)
+            >>> w, x = ConceptDriftCheckTimeSeries._reservoir_model_feature(window_data)
+        """
+        # Initialize weights
+        res_size = self._res_size
+        x_state = _w_generate(res_size, len(window_data), window_data)
+        x_state_t = x_state.T
+        # Data reshape
+        data_channel = None
+        if window_data.ndim == 2:
+            data_channel = window_data.shape[1]
+        if window_data.ndim == 1:
+            data_channel = 1
+        y_t = window_data.reshape(len(window_data), data_channel)
+        reg = 1e-8
+        # Calculate w_out
+        w_out = np.dot(np.dot(y_t, x_state_t),
+                       np.linalg.inv(np.dot(x_state, x_state_t) + reg*np.eye(res_size)))
+        return w_out, x_state
+
+    def _concept_distance(self, data_x, data_y):
+        """
+        Calculate the distance of two example blocks.
+
+        Args:
+            data_x(numpy.ndarray): Data x.
+            data_y(numpy.ndarray): Data y.
+
+        Returns:
+            distance_score_mean(float): Distance between data_x and data_y.
+
+        Examples:
+            >>> x = np.random.rand(100)
+            >>> y = np.random.rand(100)
+            >>> score = ConceptDriftCheckTimeSeries._concept_distance(x, y)
+        """
+        # Feature extraction
+        feature_x = self._reservoir_model_feature(data_x)
+        feature_y = self._reservoir_model_feature(data_y)
+        # Calculate distance
+        distance_wx = sum(abs(np.dot(feature_x[0], feature_x[1])
+                              - np.dot(feature_y[0], feature_y[1])))/len(data_x)
+        statistic_feature = abs(data_x.mean() - data_y.mean()).mean()
+        distance_score = (distance_wx + statistic_feature) / (1 + distance_wx + statistic_feature)
+        distance_score_mean = distance_score.mean()
+        return distance_score_mean
+
+    def _data_process(self, data):
+        """
+        Data processing.
+
+        Args:
+            data(numpy.ndarray): Input data.
+
+        Returns:
+            smooth_data(numpy.ndarray): Data after smoothing.
+
+        Examples:
+            >>> data_example = np.random.rand(100)
+            >>> data_example = ConceptDriftCheckTimeSeries._data_process(data_example)
+        """
+        temp = []
+        data_channel = None
+        if data.ndim == 2:
+            data_channel = data.shape[1]
+        if data.ndim == 1:
+            data_channel = 1
+        data = data.reshape(len(data), data_channel)
+        # Moving average
+        for i in range(data_channel):
+            data_av = np.convolve(data[:, i],
+                                  np.ones((self.rolling_window,)) / self.rolling_window, 'valid')
+            data_av = np.append(data_av, np.ones(self.rolling_window - 1)*data_av[-1])
+            data_av = (data_av - data_av.min()) / (data_av.max() - data_av.min())
+            temp.append(data_av)
+        smooth_data = np.array(temp).T
+        return smooth_data
+
+    def concept_check(self, data):
+        """
+        Find concept drift locations in a example series.
+
+        Args:
+            data(numpy.ndarray): Input data. The shape of data could be (n,1) or (n,m).
+                Note that each column (m columns) is one data series.
+
+        Returns:
+            drift_score(numpy.ndarray): The concept drift score of the example series.
+            threshold(float): The threshold to judge concept drift.
+            concept_drift_location(list): The location of the concept drift.
+
+        Examples：
+            >>> concept = ConceptDriftCheckTimeSeries(window_size=100, rolling_window=10,
+            >>>                   step=10, threshold_index=1.5, need_label=False)
+            >>> data_example = np.array([np.random.rand(1000),
+            >>>                          np.random.rand(1000), np.random.rand(1000)]).T
+            >>> score, drift_threshold, point = concept.concept_check(data_example)
+        """
+        # data check
+        data = _check_array_not_empty('data', data)
+        data = check_param_type('data', data, np.ndarray)
+        check_param_in_range('window_size', self.window_size, 10, int((1 / 3)*len(data)))
+        original_data = data
+        data = self._data_process(data)
+        # calculate drift score
+        drift_score = np.zeros(len(data))
+        step_size = self.step
+        for i in range(0, len(data) - 2*self.window_size, step_size):
+            data_x = data[i: i + self.window_size]
+            data_y = data[i + self.window_size:i + 2*self.window_size]
+            drift_score[i + self.window_size] = self._concept_distance(data_x, data_y)
+        threshold = _cal_threshold(drift_score, self.threshold_index)
+        # original label
+        label, label_location = _original_label(data, threshold, drift_score,
+                                                self.window_size, step_size)
+        # label continue
+        label_continue = _label_continue_process(label)
+        # find drift blocks
+        concept_drift_location, drift_point = _drift_blocks(drift_score,
+                                                            label_continue, label_location)
+        # show result
+        _plot_show(original_data, threshold, concept_drift_location,
+                   drift_point, drift_score)
+        return drift_score, threshold, concept_drift_location
+
+
+def _plot_show(original_data, threshold, concept_location, drift_point, drift_score):
+    """
+    To show the result.
+
+    Args:
+        original_data(numpy.ndarray): The input data.
+        threshold(float): The concept drift threshold.
+        concept_location(list): The concept drift locations(x-axis).
+        drift_point(list): The precise drift location of a drift.
+        drift_score(numpy.ndarray): The drift score of input data.
+    """
+    plt.figure(figsize=(20, 8))
+    plt.subplot(2, 1, 1)
+    # Plot input data and drift points
+    plt.plot(original_data, label="data")
+    plt.title('concept drift check, threshold=' + str(threshold))
+    plt.scatter(concept_location, np.ones(len(concept_location)),
+                marker='*', s=200, color="b", label="concept drift occurred")
+    for _, i in enumerate(drift_point):
+        plt.axvline(x=i, color='r', linestyle='--')
+    plt.legend()
+    plt.subplot(2, 1, 2)
+    # Plot drift score
+    plt.plot(drift_score, label="drift_score")
+    plt.axhline(y=threshold, color='r', linestyle='--', label="threshold")
+    plt.legend()
+    plt.show()
+
+
+def _original_label(original_data, threshold, drift_score, window_size, step_size):
+    """
+    To obtain a original drift label of time series.
+
+    Args:
+        original_data(numpy.ndarray): The input data.
+        threshold(float): The drift threshold.
+        drift_score(numpy.ndarray): The drift score of the input data.
+        window_size(int): Size of a concept window.
+            Usually 3 periods of the input data if it is periodic.
+        step_size(int): The jump length of the sliding window.
+
+    Returns:
+        label(list): The drift label of input data.
+            0 means no drift, and 1 means drift happens.
+        label_location(list): The locations of drifts(x-axis).
+    """
+    label = []
+    label_location = []
+    # Label: label=0, no drifts; label=1, drift happens.
+    for i in range(0, len(original_data) - 2*window_size, step_size):
+        label_location.append(i + window_size)
+        if drift_score[i + window_size] >= threshold:
+            label.append(1)
+        else:
+            label.append(0)
+    return label, label_location
+
+
+def _label_continue_process(label):
+    """
+    To obtain a continual drift label of time series.
+
+    Args:
+        label(list): The original drift label.
+
+    Returns:
+        label_continue(numpy.ndarray): The continual drift label.
+            The drift may happen occasionally, we hope to avoid
+            frequent alarms, so label continue process is necessary.
+    """
+    if label[-1] == 1 and label[-2] == 0 and label[-3] == 0 and label[-4] == 0:
+        label[-1] = 0
+    if label[0] == 1 and label[1] == 0 and label[2] == 0 and label[3] == 0:
+        label[0] = 0
+    label_continue = np.array(label)
+    # Label continue process
+    for i in range(1, len(label) - 1):
+        if label[i - 1] == 0 and label[i + 1] == 0:
+            label_continue[i - 1:i + 1] = 0
+    return label_continue
+
+
+def _find_loc(label_location):
+    return label_location[1] - label_location[0]
+
+
+def _continue_block(location):
+    """
+    Find continue blocks of concept drift.
+
+    Args:
+        location(numpy.ndarray): The locations of concept drift.
+
+    Returns:
+        area(list): Continue blocks of concept drift.
+    """
+    area = []
+    for _, loc in groupby(enumerate(location), _find_loc):
+        l_1 = [j for i, j in loc]
+        area.append(l_1)
+    return area
+
+
+def _drift_blocks(drift_score, label_continue, label_location):
+    """
+    Find the concept drift areas.
+
+    Args:
+        drift_score(numpy.ndarray): The drift score of the data series.
+        label_continue(numpy.ndarray):  The concept drift continual label.
+        label_location(numpy.ndarray):  The locations of concept drift(x-axis).
+
+    Returns:
+        concept_location(list): The concept drift locations(x-axis) after continual blocks finding.
+        drift_point(list): Return a precise beginning location of a drift.
+    """
+    # Find drift blocks
+    area = _continue_block(np.where(label_continue == 1)[0])
+    label_continue = np.array(label_continue)
+    label_location = np.array(label_location)
+    label_continue = label_continue[label_continue == 1]
+    concept_location = []
+    drift_point = []
+    # Find drift points
+    for _, lo_ in enumerate(area):
+        location = label_location[lo_]
+        concept_location.extend(location)
+        if label_continue.size > 0:
+            drift_point.append(location[np.where(drift_score[location]
+                                                 == np.max(drift_score[location]))[0]])
+        else:
+            drift_point.append(None)
+    return concept_location, drift_point
+
+
+def _w_generate(res_size, in_size, input_data):
+    """
+    Randomly generate weights of the reservoir model.
+
+    Args:
+        res_size(int): The number of reservoir nodes.
+        in_size(int): The input size of reservoir model.
+        input_data(numpy.ndarray): Input data.
+
+    Returns:
+        x_state(numpy.ndarray): The state of reservoir.
+    """
+    # Weight generates randomly
+    np.random.seed(42)
+    w_in = np.random.rand(res_size, in_size) - 0.5
+    w_0 = np.random.rand(res_size, res_size) - 0.5
+    w_0 *= 0.8
+    a_speed = 0.3
+    # Data reshape
+    data_channel = None
+    if input_data.ndim == 2:
+        data_channel = input_data.shape[1]
+    if input_data.ndim == 1:
+        data_channel = 1
+    # Reservoir state
+    x_state = np.zeros((res_size, data_channel))
+    u_input = input_data.reshape(len(input_data), data_channel)
+    for _ in range(50):
+        x_state = (1 - a_speed)*x_state + \
+                  a_speed*np.tanh(np.dot(w_in, u_input) + np.dot(w_0, x_state))
+    return x_state
+
+
+def _cal_distance(matrix1, matrix2):
+    """
+    Calculate distance between two matrix.
+
+    Args:
+        matrix1(numpy.ndarray): Input array.
+        matrix2(numpy.ndarray): Input array.
+
+    Returns:
+        distance(numpy.ndarray): Distance between two arrays.
+    """
+    w_mean_x = np.mean(matrix1, axis=0)
+    w_mean_y = np.mean(matrix2, axis=0)
+    distance = sum(abs(w_mean_x - w_mean_y))
+    return distance
+
+
+def _cal_threshold(distance, threshold_index):
+    """
+    Calculate the threshold of concept drift.
+
+    Args:
+        distance(numpy.ndarray): The distance between two data series.
+        threshold_index(float): Threshold adjusted index, [-∞, +∞].
+
+    Returns:
+        threshold(float): [0, 1].
+    """
+    distance = distance[distance > 0]
+    # Threshold calculation
+    if distance.size > 0:
+        q_1 = np.percentile(distance, 25)
+        q_3 = np.percentile(distance, 75)
+        q_diff = q_3 - q_1
+        threshold = np.clip(0.1 + threshold_index*q_diff, 0, 1)
+    else:
+        threshold = 1
+    return threshold
diff --git a/tests/ut/python/reliability/concept_drift/test_concept_drift_time_series.py b/tests/ut/python/reliability/concept_drift/test_concept_drift_time_series.py
new file mode 100644
index 0000000..6953727
--- /dev/null
+++ b/tests/ut/python/reliability/concept_drift/test_concept_drift_time_series.py
@@ -0,0 +1,52 @@
+# Copyright 2021 Huawei Technologies Co., Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Concept drift test.
+"""
+
+
+import logging
+import pytest
+import numpy as np
+from mindarmour import ConceptDriftCheckTimeSeries
+from mindarmour.utils.logger import LogUtil
+
+LOGGER = LogUtil.get_instance()
+TAG = 'Concept_Test'
+
+
+@pytest.mark.level0
+@pytest.mark.platform_arm_ascend_training
+@pytest.mark.platform_x86_ascend_training
+@pytest.mark.env_card
+@pytest.mark.component_mindarmour
+def test_cp():
+    """
+    Concept drift test.
+    """
+    # create data
+    data = 5*np.random.rand(1000)
+    data[200: 800] = 50*np.random.rand(600)
+    # initialization
+    concept = ConceptDriftCheckTimeSeries(window_size=100, rolling_window=10,
+                                          step=10, threshold_index=1.5, need_label=False)
+    # drift check
+    drift_score, threshold, concept_drift_location = concept.concept_check(data)
+    LOGGER.set_level(logging.DEBUG)
+    LOGGER.debug(TAG, '--start concept drift test--')
+    LOGGER.debug(threshold, '--concept drift threshold--')
+    LOGGER.debug(concept_drift_location, '--concept drift location--')
+    LOGGER.debug(TAG, '--end concept drift test--')
+    assert np.any(drift_score >= 0.0)