import java.io.*;
class Main{
  public static void main(String []args)throws IOException{
  	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    
    int num = Integer.parseInt(br.readLine());
    
    int happiness;
    
    happiness = (num / 500) * 1000;
    num = num % 500;
    happiness = happiness + (num / 5) * 5;
    
    System.out.println(happiness);
  }
}
/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