import acm.program.*;
import java.util.Random;
import java.awt.Font;

public class MathQuiz extends ConsoleProgram
{
    final int SIZE = 5;
    final int NUM_TRIES = 3;
    int[] nums = new int[2*SIZE];
    public void run()
    {
        GenNums();
    }
    public void GenNums()
    {
        Random rnd = new Random();
        boolean operator = rnd.nextBoolean();
        for (int i=0;i<2*SIZE;i++)
        {
            nums[i] = rnd.nextInt(21);
            print(nums[i]+" \n");
        }

        for (int i=0;i<2*SIZE;i=i+2)
            {
                int counter = NUM_TRIES;
                boolean correct = false;
                while(counter-- > 0 && !correct){
                    int num1;
                    int ans;
                    if(nums[i+1]>nums[i])
                    {
                        num1 = nums[i+1]-nums[i];
                       ans = readInt(num1+"+"+nums[i]+"= ");
                    }
                    else
                    {
                        num1 = nums[i]-nums[i+1];
                        ans = readInt(nums[i]+"-"+num1+"= ");
                    }

                    if(ans == nums[i+1])
                    {
                        println(GenResponse());
                        correct = true;
                    }
                    else
                    {
                        ans = readInt("That's incorrect - try a different answer: ");
                    }
                }
            }
    }
    public String GenResponse()
    {
        String[] response = new String[5];
        response[0]=("Correct!");
        response[1]=("That's the answer!");
        response[3]=("You got it!");
        response[4]=("Right!");
        Random rnd = new Random();
        return response[rnd.nextInt(5)];
    }
    public static void main(String[] args)
    {
        new MathQuiz().start();
    }
}