import java.util.*;
public class Main{
  
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int N=scanner.nextInt();
    int remDiv=((N%500)/5);

    int gc=((N/500)*1000)+(remDiv*5);
    System.out.println(gc);
  }

}
/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