import java.util.Scanner;
public class Main {
	public static void main(String[] args) {

//	入力の読み込み
		Scanner sc = new Scanner(System.in);
		int total = sc.nextInt();


//	500円玉が取れなくなるまで
		int count500 = 0;
		while(total >= 500) {
			total -= 500;
			count500++;
		}

//	5円玉が取れなくなるまで
		int count5 = 0;
		while(total >= 5){
			total -= 5;
			count5++;
		}

//	嬉しさの合計を表示
		System.out.print(count500*1000 + count5*5);
	}
}

/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