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


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