import java.util.Scanner;

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

        int X = Integer.parseInt(scan.next());
        scan.close();
        
        int happy = 0;

        int a = X/500;
        int b = (X%500)/5;

        happy += 1000*a + 5*b;
        
        System.out.println(happy);
        // System.out.println(a);
        // System.out.println(b);
    }
}
/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