import java.util.*;

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

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