

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	}

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

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	} main {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc long ans = 0; ans 0 while(x >=500) {
		x = x - 500;
		ans += 1000;
		} x >=500 x 500 {
		x = x - 500;
		ans += 1000;
		} x = x - 500 x x - 500 x 500 ans += 1000 ans 1000 while(x >= 5) {
			x = x - 5;
			ans += 5;
		} x >= 5 x 5 {
			x = x - 5;
			ans += 5;
		} x = x - 5 x x - 5 x 5 ans += 5 ans 5 System.out.println(ans) System.out.println System.out System System.out ans sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	}

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	}

} Main


import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();

		long ans = 0;

		while(x >=500) {
		x = x - 500;
		ans += 1000;
		}
		while(x >= 5) {
			x = x - 5;
			ans += 5;
		}

		System.out.println(ans);


		sc.close();

	}

}
