import java.util.Scanner;
class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int c = scanner.nextInt();
    System.out.println(ans(c));
  }
  
  public static int ans(int c) {
    int h = 0;
    if(c == 0) { 
      return 0;
    } else {
      int fh = c/500;
      c = c%500;
      int f = c/5;
      h = fh*1000 + f*5;
      return h;
    }
  }
}

/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