using System;

​

public class Program

{

    public static void Main()

    {

        int[] a = new int[29];

        Console.WriteLine("Enter number: 1. To find parking 2. To vacate parking 3. Exit the program");

        int num = int.Parse(Console.ReadLine());

        while (num != 3)

        {

            if (num == 1)

            {

                Console.WriteLine("Enter parking time when 00:00 is 24");

                for (int x = 0; x < a.Length; x++)

                {

                    if (a[x] == 0)

                    {

                        a[x] = int.Parse(Console.ReadLine());

                        Console.WriteLine("Your parking space is at:" + x);

                    }

                    else

                    {

                        Console.WriteLine("The parking lot is full");

                    }

                }

            }

​

            if (num == 2)

            {

                Console.WriteLine("Enter the space available in the parking lot");

                int y = int.Parse(Console.ReadLine());

                if (a[y] == 0)

                {

                    Console.WriteLine("Error");

                }

                else

                {

                    Console.WriteLine("Enter the parking clearance time");

                    int time = int.Parse(Console.ReadLine());

                    int pay = (time - a[y]) * 15;

                    a[y] = 0;

                    Console.WriteLine(pay);

                }

            }

        }

    }

}