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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 nCr(n, r):
 """ Calculates nCr. Args: n (int):
 total number of items. r (int):
 items to choose Returns: nCr. """

    f = math.factorial
    return int(f(n) / f(r) / f(n-r))