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


int main() {
    int n, m;
    cin >> n >> m;
    cout << min(n-1 + 1LL*n*(m-1),  m-1 + 1LL*m*(n-1) ) << '\n';
    return 0;
}