#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)


vll dx = { 1,-1,0 };
vll dy = { 1,-1,0 };
int main() {
    ll N,M;
    cin>>N>>M;
    N=N|M;
    M=1;
    rep(i,N)M*=i+1;
    cout<<M<<endl;
}