import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	}

} 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();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	}

} Main public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	} main {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc int result = 0; result 0 for(int i = 500;i<=x;x-=500) 
			result+=1000; int i = 500; int i = 500; i 500 i<=x i x x-=500 x-=500 x 500 result+=1000; result+=1000 result 1000 for(int j = 5;j<=x;x-=5) 
			result+=5; int j = 5; int j = 5; j 5 j<=x j x x-=5 x-=5 x 5 result+=5; result+=5 result 5 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	}

} public class Main {

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	}

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

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int result = 0;
		for(int i = 500;i<=x;x-=500) 
			result+=1000;
		for(int j = 5;j<=x;x-=5) 
			result+=5;
		
		System.out.println(result);
	}

}
