import sys
#input = sys.stdin.readline
input = sys.stdin.buffer.readline

def kaijo(x):
    ret = 1
    for i in range(1,x+1):
        ret *= i
    return ret

def main():
    a,b = map(int,input().split())
    c = a|b
    print(kaijo(c))
    
if __name__ == '__main__':
    main()