import java.util.Scanner;

public class QuizDemo
{
    public static void main(String[] args) 
    {
        int n1 = (int) (9 * Math.random() + 1);
        int n2 = (int) (9 * Math.random() + 1);
        
        if ( n1 < n2 )
        {
            // Swap n1, n2
            int h;
            h = n1;
            n1 = n2;
            n2 = h;
        }
        
        System.out.print("What is ");
        System.out.print(n1);
        System.out.print(" - ");
        System.out.print(n2);
        System.out.print(" ? ");
        
        Scanner input = new Scanner(System.in);
        
        int ans = input.nextInt();
        
        if ( ans == (n1 - n2) )
        {
            System.out.print("Correct !");
        }
        else
        {
            System.out.print("Sorry, it's not correct..");
        }
    }
}
