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);
        long n = in.nextInt();
        long m = in.nextInt();
        
        if(n==1 || m==1)
            {
            long mul=n*m;
            System.out.println(mul-1);
            }
        else
            {
            long mul1=(n-1)+((m-1)*n);
            System.out.println(mul1);
            }
    }
}