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

public class Solution {

    public static void main(String[] args) {
       Scanner scan = new Scanner(System.in);
        long n=scan.nextInt();
        long m=scan.nextInt();
        long min=0;
        long max=0;
        if(n>m){min=m;max=n;}
        else {min=n;max=m;};
        long  cut=0;
        cut=(min-1)+(min)*(max-1);
        System.out.println(cut);
    }
}