#include <bits/stdc++.h>
using namespace std;
using G=vector<vector<int>>;
typedef long long ll;
#define rep(i,l,r) for(int i=(l);i<(r);++i)

int main(){
	int a,b; cin>>a>>b;
	int c=a|b;
	ll ans=1;
	rep(i,1,c+1) ans*=i;
	cout<<ans<<endl;
}