package ru.pangaia.arithmo;

import java.util.InputMismatchException;
import java.util.NoSuchElementException;
import java.util.Random;
import java.util.Scanner;

public class MathTest {

    private static Random rnd = new Random();

    public static void main(String[] args) {
	// write your code here
        try {
            int time = Integer.parseInt(args[0]);
            Long timerMillis = new Long(time*60*1000);
            displayGreeting(time);
            Scanner scanner = new Scanner(System.in);
            Long startTime = System.currentTimeMillis();
            int counter = 0;
            int rightAnswers = 0;
            while (System.currentTimeMillis()-startTime < timerMillis)
            {
                counter++;

                try {
                    if(showMiniTask() == scanner.nextInt())
                    {
                        rightAnswers++;
                    }
                }
                catch(InputMismatchException ex) {break;}
                catch(NoSuchElementException ex) {break;}
            }
            displayStats(time,counter,rightAnswers);
        }
        catch (NumberFormatException ex) {
            System.exit(1);
        }

    }
    public static void displayGreeting(int time) {
        System.out.printf("Please enter answers for math questions\nyou have %d minutes\n",time);
        System.out.println("===========Start!==========");

    }
    public static void displayStats(int time,int tot,int right) {
        System.out.printf("\ntimer for %d minutes, correct/total: %d/%d\n", time, right, tot);
    }
    public static int showMiniTask() {
        int a = rnd.nextInt(10);
        int b = rnd.nextInt(10);
        int c = rnd.nextInt(10);
        int pm1 = rnd.nextInt(2);
        int pm2 = rnd.nextInt(2);
        System.out.printf("%d %s %d %s %d = ",a,pm1==0?"+":"-",b,pm2==0?"+":"-",c);
        int result = 0;
        result +=a;
        if (pm1==0) {
            result+=b;
        }
        else {
            result-=b;
        }
        if (pm2==0){
            result+=c;
        }
        else {
            result-=c;
        }
        return result;
    }
}