UVA 10970 - Big Chocolate

#include <bits/stdc++.h>
#define EPS 1e-9
#define PI 3.14159265359
#define ii pair<int, int>

typedef long long ll;

using namespace std;

int main()
{
    int m, n;
    while(scanf("%d%d", &m, &n) == 2){
        printf("%d\n", m - 1 + m * (n - 1));
    }
}