import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
      int x = sc.nextInt();
      int happy = 0;
      int cnt1 = 0;
      int cnt2 = 0;
      while(x>=500){
         cnt1++;
         x = x-500;
      }
      happy += 1000*cnt1;
      while(x>=5){
         cnt2++;
         x = x-5;
      }
      happy += 5*cnt2;
      System.out.println(happy);     
   }
}
/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