import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int m = in.nextInt();
        int cuts = 0;
        int max, min;
        if (n >= m) {
            max = n;
            min = m;
        }
        else {
            max = m;
            min = n;
        }
        
        
        if (max>1) cuts = cuts + (max-1);
        if (min>1) cuts = cuts + (max) * (min-1);
        System.out.println(cuts);
        
        
        
        
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
    }
}