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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    long long a, b;
    cin >> a >> b;
    cout << fixed << min(a-1, b-1)+ max(1ll,min(a, b))*max(a-1, b-1);
    return 0;
}