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 in=new Scanner(System.in);
        int n=in.nextInt();
        int m=in.nextInt();
        long cut=n-1;
        cut+=(long) (n)*(m-1);
        System.out.println(cut);
    }
}