code: import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.util.LinkedList;
  
  public class License {
    public static void main(String[] args) throws FileNotFoundException, IOException{
      BufferedReader in = new BufferedReader(new FileReader(args[0]));
      int max = Integer.MIN_VALUE;
      LinkedList<String> dates = new LinkedList<String>();
      String line;
      int count = 0;
      while((line = in.readLine()) != null){
        if(line.startsWith("License OUT ")) count++;
        if(line.startsWith("License IN ")) count--;
        if(count > max){
          max = count;
          String date = line.split(" ")[3];
          dates.clear();
          dates.add(date);
        }else if(count == max){
          String date = line.split(" ")[3];
          dates.add(date);
        }
      }
      System.out.println("Max licenses out: "+max);
      System.out.println("At time(s): "+dates);
    }
  }
  