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


int main() {
    long long k, n;
  cin >> k >> n;
  long long less =min(k, n);
  long long more = max(k, n);
  cout << (less * (more - 1) + less - 1) << endl;
    return 0;
}