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: Wrong Answer)

using System;


class Program
{
    static void Main(string[] arg)
    {
        var res = int.Parse(Console.ReadLine().ToString());
      	
      
      	
        Console.WriteLine(CalcTakahashiPoint(res));
    }
    static int CalcTakahashiPoint(int money)
    {
        var a = money / 500.0f;
        var b = (int)Math.Floor(a);
        var c = money - (b * 500);

        var d = c / 5.0f;
        var e = (int)Math.Floor(a);

        return (b * 10000 + e * 5);
    }
    
  
}