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

    static void Main(String[] args) {
        string[] tokens_n = Console.ReadLine().Split(' ');
        long n = Convert.ToInt64(tokens_n[0]);
        long m = Convert.ToInt64(tokens_n[1]);
         if(n<m) {
            long temp = n;
            n = m;
            m = temp;
}
        Console.WriteLine((n-1)+(n*(m-1)));
    }
}