import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int X = sc.nextInt();

        int c500 = X / 500; // 500円枚数
        int c = X % 500;
        int c5 = c / 5; // 5円枚数

        System.out.print((c500*1000) + (c5*5));
    }
}
/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