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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 merge_paths(paths, weights=None):
 """ Zip together sorted lists. [1, 2, 3, 4, 5] [1, 2, 3, 4] """

    G = make_paths(paths, weights=weights)
    G = reduce_paths(G)
    return G