using System;
using System.Collections.Generic;
using System.IO;
class Solution {

    static void Main(String[] args) {
        string[] tokens_n = Console.ReadLine().Split(' ');
        int n = Convert.ToInt32(tokens_n[0]);
        int k = Convert.ToInt32(tokens_n[1]);
        int l;
        int s;
        if (n>k){
          l=n;
          s=k;  
        } 
        else {
          l = k;
          s = n;
        }
        l--;
        s--;
        long res = (long)s + ((long)s+1)*(long)l;
        Console.WriteLine(res);
    }
}