using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        long[] ar = Array.ConvertAll(Console.ReadLine().Split(), Int64.Parse);
        long n = Math.Min(ar[0],ar[1]);
        long m = Math.Max(ar[0],ar[1]);
        
        Console.WriteLine((m-1) + m*(n-1));
    }
}