#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

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