import java.util.*;

public class Main{
public static void main(String args[]){
	
	Scanner sc = new Scanner(System.in);
	int C = sc.nextInt();
	
	int a = C%500;
	int b = (a-(a%5));
	int c = (C-a)*2;
	
	System.out.println(b+c);
}
}
/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