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 9.2.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
 
#define IOS ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define int long long
#define rep(i,a,b)    for(int i=a;i<b;i++)
#define repn(i,a,b)   for(int i=a;i>=b;i--)
#define F first
#define S second
#define pii pair<int,int>
#define vi vector<int>
#define vii vector<pii>
#define pb push_back
#define mp  make_pair
#define all(v) (v).begin(), (v).end()
#define mod 1000000007
#define inf 1e18 
 
using namespace std;
 
signed main()
{
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output1.txt", "w", stdout);
    #endif
    
    IOS;
    int x;
    cin>>x;
    int ans=0;
    ans=x/500*1000+(x-x/500*500)/5*5;
    cout<<ans;
}