def ncr(n, r):
    if (r == 0):
        return 1
    r = min(r, (n - r))
    numerator = reduce(op.mul, range(n, (n - r), (- 1)), 1)
    denominator = reduce(op.mul, range(1, (r + 1)), 1)
    return (numerator / denominator)
def ncr(n, r):
    if (r == 0):
        return 1
    r = min(r, (n - r))
    numerator = reduce(op.mul, range(n, (n - r), (- 1)), 1)
    denominator = reduce(op.mul, range(1, (r + 1)), 1)
    return (numerator / denominator)