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


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