#include <bits/stdc++.h>
using namespace std;

#define ll long long

int main() 
{
    ll a,b; cin>>a>>b;
    ll mn = min(a,b);
    ll mx = max(a,b);
    ll sum=0, ans=0;
    for(ll i=mn; i>=1; i--){
      ans += (i*mx);
      //cout<<ans<<endl;
      mx--;
    }
    cout << ans << endl;
    return 0;
}