diff --git a/utils.py b/utils.py
index fc2fe6d..d3f7ead 100644
--- a/utils.py
+++ b/utils.py
@@ -206,6 +206,26 @@ def last_consecutive( list_ ):
             else: # if inside the consecutive list and last element, every element is consecutive
                 break
     return i
+def same_value( list_ ):
+    """
+    divide a sorted list of integer by same value part
+    """
+    if not isinstance( list_ , list ) and not isinstance( list_ , np.ndarray ):
+        raise ValueError( 'list_ must be a list, ' + type( list_ ) + ' given' )
+    if len( list_ ) == 0:
+        return list_
+    index = last_same_value( list_ )
+    if index == len( list_ ) - 1:
+        return [ list_ ]
+    return same_value( list_[ : index + 1 ] ) + same_value( list_[ index + 1 : ] )
+def last_same_value( list_ ):
+    """
+    return the last index of the first same value list
+    """
+    if not isinstance( list_ , list ) and not isinstance( list_ , np.ndarray ):
+        raise ValueError( 'list_ must be a list, ' + type( list_ ) + ' given' )
+    value = list_[0]
+    return np.argwhere( list_ == value ).max()
 def rotate( image , angle ):
     """
     rotate the following image by the given angle