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;

namespace _160abc
{
    class Program
    {
        static void Main(string[] args)
        {     
            long X = long.Parse(Console.ReadLine());
            long resfff = 0;
            long resf = 0;
            resfff = X/500;
            resf = (X-X/500*500)/5;
            Console.WriteLine(resfff*1000+resf*5);
            // string S = Console.ReadLine();
            // bool flag = true;
            // if(S[2]==S[3] && S[4]==S[5]){
            //     flag = true;
            // }else{
            //     flag = false;
            // }
            // Console.WriteLine(flag? "Yes":"No");
        }
    }
}