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.ToInt32(tokens_n[0]);
        long m = Convert.ToInt32(tokens_n[1]);
        long min = Math.Min(m, n);
            long max = Math.Max(m, n);
            long sum = min - 1 + min * (max - 1);
            Console.WriteLine(sum);
    }
}