import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		        Scanner sc = new Scanner(System.in);
		        int money = sc.nextInt();

		        int point = 0;
		        //moneyが5以上ならくり返す
		        while(money >= 5) {
		        	//moneyが500以上か
		        	if(money >=500){
		        		point += 1000;
		        		money -= 500;
		        	}
		        	else if(money >= 5) {
		        		point += 5 ;
		        		money -= 5;
		        	}


		        }
		        System.out.println(point);
	}


}

/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