import java.io.*;

public class Main {
  
  static long n;

  public static void main(String[] args) throws IOException {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    String[] in;
    in = br.readLine().split(" ");
    n = Long.parseLong(in[0]);

    br.close();

    long ans = 0;
    ans += (n / 500) * 1000;
    n -= n / 500 * 500;

    ans += n / 5 * 5;
    
    System.out.println(ans);
  }
}
/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