#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 << min(n - 1 + n * (m - 1), m - 1 + m * (n - 1)) << endl;
    return 0;
}