using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
        var inputs = Console.ReadLine().Split(' ');
        
        var x = Convert.ToInt64(inputs[0]);
        var y = Convert.ToInt64(inputs[1]);
        
        long output = 0;
        
           output = y - 1;
           output += y * (x - 1); 

        
        Console.Write(output);
    }
}