import java.util.Scanner;
public class Main {public static void main(String...args){
    Scanner sc = new Scanner(System.in); int X = sc.nextInt(); int ans = 0;
    ans = ans + (X/500)*1000; X = X -  (X/500)*500; ans = ans + (X/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