.编写函数，计算20*19*18*…*3的结果

def lazy_product(*args):
    def product():
        result = 1
        for arg in args:
            result *= arg
        return result
    return product

f = lazy_product(20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3)
print(f())  # 输出：121645100408832000