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


int main() {
    long long int n,m;
    cin>>n>>m;
    long long int a=n-1,b=m-1;
    /*if(a!=0&&b!=0)cout<<;
    else if(a==0)cout<<b;
    else if(b==0)cout<<a;
    else cout<<"0";
    */
    if(n>m){
        cout<<b+(a*m);
    }
    else{
        cout<<a+(b*n);
    }
    return 0;
}