import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int n = sc.nextInt();
        int hap = 0;
        int fives = n % 500;
        int num500 =n  / 500;
        int num5 =  fives / 5;
        hap += (num500 * 1000) + (num5 * 5);
        System.out.println(hap);
    }
}

/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