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

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long m = in.nextLong();
        long n = in.nextLong();
        
        long larger = (m>=n) ? m : n;
        long smaller = (m>=n) ? n :m;
        
        System.out.println((smaller-1) + (smaller*(larger-1)));
    }
}