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


int main() {
    long  n,m;
    cin>>n>>m;
    long newn,newm;
    if(n>m){
        newn=m;
        newm=n;
    }
    else{
        newn=n;
        newm=m;    
    }
    cout<<(newn-1)+(newn*(newm-1))<<endl;
    
    return 0;
}