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++14 (GCC 5.4.1) (judge verdict: Accepted)

/*

*/
#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <iomanip>
#include <set>
#include <map>
#include <stack>
#include <deque>
 
#define ll long long
#define cint const int
#define ld long double
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define pb push_back
#define fi first
#define se second
 
using namespace std;

int n, m, a[1000005];

int main () {
	cin >> n;
	int m = n % 500;
	m -= m % 5;
	cout << ((n / 500) * 1000) + m;
	return 0;
}