import java.util.Scanner;
 
public class Main {
 
	public static void main(String[]args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int happynesspoint,k,j;
		if(n>=0){
			k = n/500;
			j= n%500;
			happynesspoint = 1000*k+5*(j/5);
		System.out.println(happynesspoint);
	}
}
}
/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