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

public class Solution 
{
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long m = sc.nextLong();
        long s;
        if(n>m)
            s = m;
        else
            s=n;
        long l = (n+m)-s;
        long ans = (s-1) + (l-1)*(s-1); 
        
        
        System.out.println((n*m)-1);
        
    }
}