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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <string.h>

#define YEN_500 500
#define YEN_5 5
#define HAPPINESS_POINTS_LARGE 1000
#define HAPPINESS_POINTS_SMALL 5

int main()
{
    long moneyInput, fiveHundreadCoinsAmount, fiveCoinsAmount;

    scanf("%ld", &moneyInput);

    if (moneyInput / YEN_500 > 0)
    {   // Count amount of 500 and 5 Yen coins
        fiveHundreadCoinsAmount = moneyInput / YEN_500;
        fiveCoinsAmount = (moneyInput % YEN_500) / YEN_5;
        // Counts points for every coin
        printf("%ld \n", (fiveHundreadCoinsAmount * HAPPINESS_POINTS_LARGE) + (fiveCoinsAmount * HAPPINESS_POINTS_SMALL));
    }
    else if (moneyInput / YEN_500 <= 0)
    {
        // Count amount of 5 Yen coins
        fiveCoinsAmount = (moneyInput % YEN_500) / YEN_5;
        // Counts points for every coin
        printf("%ld \n",(fiveCoinsAmount * HAPPINESS_POINTS_SMALL));
    }

    return 0;
}