using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        while (true)

        {

            Dictionary<int, int> dict = new Dictionary<int, int>();

            Random key = new Random(); //random key

            Random prize = new Random(); //prize money

            for (int i = 0; i < 10; i++)

            {

                int k;

                int p;

                while (true)

                {

                    k = key.Next(1, 21);

                    dict.TryGetValue(k, out p); //10 distinct random num

                    if (p != 0)

                    {

                        continue;

                    }

​

                    dict.Add(k, prize.Next(1, 10001));

                    break;

                }

            }

​

            /* foreach(KeyValuePair<int, int> pair in dict)

        {

            Console.WriteLine("Key = {0}, Value = {1}", pair.Key, pair.Value); 

        }       */

            Console.WriteLine("Please input two integers (both from 1 to 20,in one line):");

            List<int> list = new List<int>();

            string input = Console.ReadLine();

            string[] tokens = input.Split();

            foreach (string s in tokens)

            {

                int num;

                bool success = int.TryParse(s, out num); // TryParse returns true if successfully converted s into an int 

                // the converted int is put into the second parameter using keyword "out"   

                // do you know why "out" is used here? why not return the converted integer?

                if (success)

                {

                    list.Add(num); // add num to list if success

                }

            }

​

            if (list[0] == list[1]) //not distinct

            {

                Console.WriteLine("quit");

                break;

            }

            else if ((list[0] >= 1 && list[0] <= 20) && (list[1] >= 1 && list[1] <= 20))

            {

                int value1;

                int value2;

                dict.TryGetValue(list[0], out value1);

                dict.TryGetValue(list[1], out value2);

                Console.WriteLine("You earned " + (value1 + value2) + " in total!");

            }

            else //out of range

            {

                Console.WriteLine("quit");

                break;

            }

        }

    }

}