#include <iostream>
#include <cstdio>
using namespace std;
long long int factorial(long long int num) {
if(num == 1 || num == 0) return 1;
return num * factorial(num - 1);
}
int main() {
long long int M, N;
while (scanf("%lli %lli", &M, &N) != EOF) cout << factorial(M) + factorial(N) << endl;
}
//https://pt.stackoverflow.com/q/396814/101
I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8Y3N0ZGlvPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKbG9uZyBsb25nIGludCBmYWN0b3JpYWwobG9uZyBsb25nIGludCBudW0pIHsKICAgIGlmKG51bSA9PSAxIHx8IG51bSA9PSAwKSByZXR1cm4gMTsKICAgIHJldHVybiBudW0gKiBmYWN0b3JpYWwobnVtIC0gMSk7Cn0KCmludCBtYWluKCkgewogICAgbG9uZyBsb25nIGludCBNLCBOOwogICAgd2hpbGUgKHNjYW5mKCIlbGxpICVsbGkiLCAmTSwgJk4pICE9IEVPRikgY291dCA8PCBmYWN0b3JpYWwoTSkgKyBmYWN0b3JpYWwoTikgPDwgZW5kbDsKfQoKLy9odHRwczovL3B0LnN0YWNrb3ZlcmZsb3cuY29tL3EvMzk2ODE0LzEwMQ==