/**
 * Created by nishant on 10/18/2016.
 */
import  java.util.*;
public class Solution {

    public  static  void  main(String [] args){
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        long b = sc.nextLong();
        
            long x = Math.min(a,b);
            long y = Math.max(a,b);
            System.out.print((x-1)+ x*(y-1) );
        
    }

}