import sys
input = lambda : sys.stdin.readline().rstrip()

write = lambda x: sys.stdout.write(x+"\n")
debug = lambda x: sys.stderr.write(x+"\n")
writef = lambda x: print("{:.12f}".format(x))
# sys.setrecursionlimit(3*10**5+10)

a,b = list(map(int, input().split()))
v = a|b
ans = 1
for i in range(1, v+1):
    ans *= i
print(ans)