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 scan=new Scanner(System.in);
        long x=scan.nextLong();
        long y=scan.nextLong();
        if(y==1)
            System.out.println(x-1);
        else{
       long m=y-1;
            long n=(x-1)*y;
            long ans=m+n;
            System.out.println(ans);
        }
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
    }
}