import java.util.Scanner;

public class Main {
	public static void main(String args[]) {
		Scanner in = new Scanner(System.in);
		int x = in.nextInt();
      	
      	int numberof500 = x/500;
        int remainder = x%500;
        int numberof5 = remainder/5;
      	long ans = 1000*numberof500+5*numberof5;
      
      System.out.println(ans);
	}
}

/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