Problem:
Score : 100 points

Problem Statement

Snuke has a favorite restaurant.

The price of any meal served at the restaurant is 800 yen (the currency of Japan), and each time a customer orders 15 meals, the restaurant pays 200 yen back to the customer.

So far, Snuke has ordered N meals at the restaurant.
Let the amount of money Snuke has paid to the restaurant be x yen, and let the amount of money the restaurant has paid back to Snuke be y yen.
Find x-y.

Constraints

1 ≤ N ≤ 100

Input

The input is given from Standard Input in the following format:

N

Output

Print the answer.

Sample Input 1

20

Sample Output 1

15800

So far, Snuke has paid 16000 yen, and the restaurant has paid back 200 yen. Thus, the answer is 15800.

Sample Input 2

60

Sample Output 2

47200

Snuke has paid 48000 yen for 60 meals, and the restaurant has paid back 800 yen.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace ABC_055_A_Csharp_ver
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int n = 0;
            if (N < 15)
            {
                Console.WriteLine(N * 800);
            }
            else if (N >= 15 && N < 30)
            {
                Console.WriteLine(N * 800 - 200);
            }
            else if (N >= 30 && N < 45)
            {
                Console.WriteLine(N * 800 - 400);
            }
            else if (N >= 45 && N < 60)
            {
                Console.WriteLine(N * 800 - 600);
            }
            else if (N >= 60 && N < 75)
            {
                Console.WriteLine(N * 800 - 800);
            }
            else if (N >= 75 && N < 90)
            {
                Console.WriteLine(N * 800 - 1000);
            }
            else if (N >= 90)
            {
                Console.WriteLine(N * 800 - 1200);
            }
            Console.ReadKey();
        }
    }
}