import java.util.Scanner;
public class Main {
	 public static void main(String args[]){
	Scanner scanner = new Scanner(System.in);

	int n=scanner.nextInt();
	int i=0;
	int m=0;

		
			i=n/500;
			n=n-500*i;
		
			m=n/5;
			
			System.out.println(1000*i+5*m);
	

	 }
}
/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