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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def append_s(value):
 """ Adds the possessive s after a string. value = 'Hans' becomes Hans' and value = 'Susi' becomes Susi's """

    if value.endswith('s'):
        return u"{0}'".format(value)
    else:
        return u"{0}'s".format(value)