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


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