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();
        long max = m;
        long min = n;
        if(m < n){
            max = n;
            min = m;
        }
        long result = (min - 1) + ((max - 1)*min);
  //      if(result == 0){
 //           result = max - 1;
//        }
        System.out.println(result);
    }
}