#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

long long n,m,ans,a,b;
int main() {
    
   cin>>n>>m;
  a=max(n,m);
    b=min(n,m);
    ans=(a-1)+(a*(b-1));
    cout<<ans<<endl;
    return 0;
}