import java.util.*;
import java.math.*;

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

/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