import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        
        Scanner input = new Scanner(System.in);
        int N = input.nextInt();
        int M = input.nextInt();
        int maximum =  Math.max(M,N);
        int minimum =  Math.min(M,N);
        long answer = (maximum-1) + maximum*(minimum-1);
        
        System.out.println(answer);
    }
}