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


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