from collections import *
from itertools import *
import sys


def debug(*args, end="\n"):
    print(*args, end=end, file=sys.stderr)


sys.setrecursionlimit(10 ** 6)
MOD = 998244353

trick, treat = map(int, input().split())
ans = 1
for i in range(1, (trick | treat) + 1):
    ans *= i
print(ans)
debug("ans")