import java.util.Scanner;

/**
 * B - Golden Coins
 */
public class Main {
  @SuppressWarnings("resource")
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int val = 0;
    if (N != 0) {
      val = (N / 500) * 1000;
      val += (N % 500) / 5 * 5;
    }

    System.out.println(val);
  }
}
/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