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: Wrong Answer)

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



namespace VS_TopCoder
{

    public class ANewHope
    {
        public int count(int[] firstWeek, int[] lastWeek, int D)
        {
            int N = firstWeek.Length;
            int shift = N - D;
            int ma = 1;
            for (int i = 0; i < N; i++)
            {
                for (int j = 0; j < N; j++)
                {
                    if(firstWeek[i]==lastWeek[j] && j < i)
                    {
                        int d = i - j;
                        ma = Math.Max(ma, (d + shift - 1) / shift + 1);
                    }
                }

            }

            return ma;

        }


    }

    class Program
    {

        static void Main(string[] args)
        {
            Test();

            var N = Convert.ToInt32(Console.ReadLine());
            var mul = N / 15;

            int answer = mul * 15 * 800  -  mul * 200;

            Console.WriteLine(answer);
            

        }


        static List<string> Readlines()
        {
            List<string> answer = new List<string>();

            do
            {
                var item = Console.ReadLine();
                if (item == null)
                {
                    break;
                }
                else
                {
                    answer.Add(item);
                }
            } while (true);

            return answer;
        }

        static List<string[]> Readlines2D(string divider)
        {
            List<string[]> answer = new List<string[]>();

            do
            {
                var item = Console.ReadLine();
                if (item == null)
                {
                    break;
                }
                else
                {
                    answer.Add(item.Split(Convert.ToChar(divider)));
                }
            } while (true);

            return answer;
        }

        //priority queue


        [Conditional("DEBUG")]
        static private void Test()
        {
            Console.SetIn(new System.IO.StreamReader(@"c:\users\user\documents\visual studio 2015\Projects\VS TopCoder\VS TopCoder\Test.txt"));
        }
    }
    class PriorityQueue<T>
    {
        private readonly List<T> heap;
        private readonly Comparison<T> compare;
        private int size;
        public PriorityQueue() : this(Comparer<T>.Default) { }
        public PriorityQueue(IComparer<T> comparer) : this(16, comparer.Compare) { }
        public PriorityQueue(Comparison<T> comparison) : this(16, comparison) { }
        public PriorityQueue(int capacity, Comparison<T> comparison)
        {
            heap = new List<T>(capacity);
            compare = comparison;
        }
        public void Enqueue(T item)
        {
            heap.Add(item);
            var i = size++;
            while (i > 0)
            {
                var p = (i - 1) >> 1;
                if (compare(this.heap[p], item) <= 0)
                    break;
                this.heap[i] = heap[p];
                i = p;
            }
            this.heap[i] = item;

        }
        public T Dequeue()
        {
            var ret = this.heap[0];
            var x = this.heap[--size];
            var i = 0;
            while ((i << 1) + 1 < size)
            {
                var a = (i << 1) + 1;
                var b = (i << 1) + 2;
                if (b < size && compare(heap[b], heap[a]) < 0) a = b;
                if (compare(heap[a], x) >= 0)
                    break;
                heap[i] = heap[a];
                i = a;

            }
            heap[i] = x;
            heap.RemoveAt(size);
            return ret;
        }

        public T Peek() { return heap[0]; }
        public int Count { get { return size; } }
        public bool Any() { return size > 0; }



    }


}