
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	}

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

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int ans = 0; ans 0 ans += N/500*1000 ans N/500*1000 N/500 N 500 1000 N -= N/500*500 N N/500*500 N/500 N 500 500 ans += N/5*5 ans N/5*5 N/5 N 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) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	}

} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	}

} Main

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans = 0;
		ans += N/500*1000;
		N -= N/500*500;
		ans += N/5*5;
		System.out.println(ans);
	}

}
