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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;

class Class_
{
	void Test()
	{
		var N = A_Int_()[0];

		var c = N * 800;
		var d = N / 15 * 200;
		
		Console.WriteLine(c-d);

	}

	static void Main(string[] args)
  {
    new Class_().Test();
  }

  #region

  string S_String_()
  {
    return Console.ReadLine();
  }

	//
	string[] A_String_()
  {
    return Console.ReadLine().Split();
  }

  int[] A_Int_(int n)
  {
    var x = new int[n];
    for (var i = 0; i < n; i++)
    {
      x[i] = int.Parse(Console.ReadLine());
    }
    return x;
  }

	//
	int[] A_Int_()
  {
    var ss = Console.ReadLine().Split();

    var x = new int[ss.Length];
    for (var i = 0; i < ss.Length; i++)
      x[i] = int.Parse(ss[i]);

    return x;
  }
  #endregion
}