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) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
    Scanner sc  = new Scanner(System.in);
        long n = sc.nextInt();
        long m = sc.nextInt();
        long a=0;
        long b=0;
    if(n>=m){
        a= n;
        b=m;
    }else{
    a= m;
    b=n;
    }
        System.out.println(b-1+ (a-1)*b);
        
    }
}