import java.util.ArrayDeque;
import java.lang.reflect.Array;
import java.util.Arrays;

import sun.tools.jar.resources.jar;

import java.util.*;

public class Main {

  public static void main(String args[]) {
    Scanner sc = new Scanner(System.in);
    long N = sc.nextInt();
    long a = N / 500;
    N %= 500;
    long b = N / 5;
    System.out.println(1000 * a + (5 * b));
  }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz