import java.util.*;

class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int X = sc.nextInt();
    
    int X_500 = X / 500;
    if (X%500 > 0){
      int X_5 = (X - X_500*500)/5;
      System.out.println(X_500*1000+X_5*5);
    }
    else
      System.out.println(X_500*1000);
    
  }
}
/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