using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Cutting_Paper_Squares
{
    class Program
    {
        static void Main(string[] args)
        {
            long[] mXn = Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);

            long n = mXn[0];
            long m = mXn[1];

            long firstCut,secondCut;

            firstCut = Math.Max(n,m);
            secondCut= Math.Min(n,m);

            long res = firstCut - 1 + firstCut * (secondCut - 1);

            Console.WriteLine(res);
        }
    }
}