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 */
        
        int[] nm = Array.ConvertAll(Console.ReadLine().Split(' '), Int32.Parse);
        
        long a = nm[0];
        long b = nm[1];
        
        if (a > b)
        {
            long temp = a;
            a = b;
            b = temp;
        }
        
        long result = a-1;
        
        result += a*(b-1);
        
        Console.WriteLine(result);
    }
}