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


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