Problem:
Score : 200 points

Problem Statement

Takahashi loves gold coins. He gains 1000 happiness points for each 500-yen coin he has and gains 5 happiness points for each 5-yen coin he has. (Yen is the currency of Japan.)

Takahashi has X yen. If he exchanges his money so that he will gain the most happiness points, how many happiness points will he earn?

(We assume that there are six kinds of coins available: 500-yen, 100-yen, 50-yen, 10-yen, 5-yen, and 1-yen coins.)

Constraints

0 \leq X \leq 10^9

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

Print the maximum number of happiness points that can be earned.

Sample Input 1

1024

Sample Output 1

2020

By exchanging his money so that he gets two 500-yen coins and four 5-yen coins, he gains 2020 happiness points, which is the maximum number of happiness points that can be earned.

Sample Input 2

0

Sample Output 2

0

He is penniless - or yenless.

Sample Input 3

1000000000

Sample Output 3

2000000000

He is a billionaire - in yen.

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

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleTest
{
    class Program
    {
        
        static void Main(string[] args)
        {
            var v = MyIo.Int();
            int num500 = v / 500;
            int num5 = (v % 500) / 5;
            int u = num500 * 1000 + num5 * 5;
            Console.WriteLine(u.ToString());

           
        }

    }
    static class MyIo
    {
        public static int Int()
        {
            return int.Parse(Console.ReadLine());
        }
        public static int[] Ints()
        {
            return Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
        }
        public static int[][] MultiInts(int num)
        {
            var result = new int[num][];
            for(int i = 0; i < num; ++i)
            {
                result[i] = Ints();
            }
            return result;
        }
        public static T[] MultiItems<T>(int num, Func<string,T> parser)
        {
            var result = new T[num];
            for(int i =0; i < num; ++i)
            {
                result[i] = parser(Console.ReadLine());
            }
            return result;
        }
    }
}