import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner (System.in);
        int x = in.nextInt();
        int z,y,a,m;
        z = x/500;
        y = z * 1000;
        z = z * 500;
        z = (x-z)/5;
        a = z * 5;
        m = a + y;
        System.out.println(m);
    }
}

/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