import java.util.Scanner;

public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		int money = scan.nextInt();
		int yen500 = 0;
		int yen5 = 0;

		for(;;) {
			if(money >= 500) {
				money -= 500;
				yen500 += 1;
			}else {
				break;
			}
		}
		for(;;) {
			if(money >= 5) {
				money -= 5;
				yen5 += 1;
			}else {
				break;
			}
		}
		System.out.println(yen500 * 1000 + yen5 * 5);

		scan.close();
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz