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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 mul(left, right):
 """ Distribution multiplication. Args: left (Dist, numpy.ndarray) : left hand side. right (Dist, numpy.ndarray) : right hand side. """

    from .mv_mul import MvMul
    length = max(left, right)
    if length == 1:
        return Mul(left, right)
    return MvMul(left, right)