import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

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

	public static void main(String[] args) {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

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

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

	} main {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int S = sc.nextInt(); S sc.nextInt() sc.nextInt sc int totalHappy = 0; totalHappy 0 totalHappy += (S/500) * 1000 totalHappy (S/500) * 1000 (S/500) S 500 1000 S = S%500 S S%500 S 500 totalHappy += (S/5) * 5 totalHappy (S/5) * 5 (S/5) S 5 5 S = S%5 S S%5 S 5 System.out.println(totalHappy) System.out.println System.out System System.out totalHappy String[] args args public class Main {

	public static void main(String[] args) {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

	}
} public class Main {

	public static void main(String[] args) {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

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

		int totalHappy = 0;
        	totalHappy += (S/500) * 1000;
        	S = S%500;
        	totalHappy += (S/5) * 5;
        	S = S%5;
        	System.out.println(totalHappy);

	}
}