// code by Juan Torres
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*5;
		System.out.println(ans);
		
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*5;
		System.out.println(ans);
		
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*5;
		System.out.println(ans);
		
	} main {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*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 int y = x/500; y x/500 x 500 int z = (x%500)/5; z (x%500)/5 (x%500) x 500 5 int ans = y*1000 + z*5; ans y*1000 + z*5 y*1000 y 1000 z*5 z 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 x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*5;
		System.out.println(ans);
		
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = x/500;
		int z = (x%500)/5;
		int ans = y*1000 + z*5;
		System.out.println(ans);
		
	}
} Main
// code by Juan Torres
import java.util.*;

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