def main():
    trick, treat = map(int, input().split())
    trick_or_treat = trick | treat
    print(factorical(trick_or_treat))


def factorical(num: int) -> int:
    fact = 1
    if num == 0: 
        return 1
    else:
        while num > 1: 
            fact *= num 
            num -= 1
        return fact 


if __name__ == "__main__":
    main()