import java.util.Scanner;

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

        long haveMoney = sc.nextLong();
        long pleasure = 0;
        while(500 <= haveMoney){
            haveMoney -= 500;
            pleasure += 1000;
        }
        while(5 <= haveMoney){
            haveMoney -= 5;
            pleasure += 5;
        }
        System.out.println(pleasure);
    }
}
/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