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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

/**
 * B - Golden Coins
 * 高橋君は金色の硬貨が好きです。
 * 自分が持っている 500 円硬貨 1 枚につき 1000、5 円硬貨 1 枚につき 5 の 嬉しさ を得ます。
 * 高橋君は X 円を持っています。
 * これを高橋君の嬉しさが最大になるように両替したとき、高橋君の嬉しさはいくらになりますか？
 * (なお、利用できる硬貨は 500 円玉、100 円玉、50 円玉、10 円玉、5 円玉、1 円玉の 6 種類とします。)
 */
public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner( System.in );
        // 高橋くんの所持金
        int x = sc.nextInt();
        // 嬉しさ
        int happiness = 0;
        happiness  = ( x / 500 ) * 1000;
        happiness += ( ( x % 500 ) / 5 ) * 5;

        System.out.println( happiness );

        sc.close();
    }
}