import java.io.FileNotFoundException;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	}
} import java.io.FileNotFoundException; FileNotFoundException java.io import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	}
} Main public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	} main {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int X = sc.nextInt(); X sc.nextInt() sc.nextInt sc sc.close() sc.close sc int ans = (X/500)*1000+(X%500)/5*5; ans (X/500)*1000+(X%500)/5*5 (X/500)*1000 (X/500) X 500 1000 (X%500)/5*5 (X%500)/5 (X%500) X 500 5 5 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	}
} public class Main {
	public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	}
} Main
import java.io.FileNotFoundException;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws FileNotFoundException {

		//    	File file = new File("src/in.txt");
		//    	Scanner sc = new Scanner(file);

		Scanner sc = new Scanner(System.in);

		int X = sc.nextInt();
		sc.close();
		int ans = (X/500)*1000+(X%500)/5*5;
		System.out.println(ans);

	}
}
