How to run the code: 
Write in the terminal "java .\BulbsProblem.java file", where the file is the name of a txt file containing the configuration of the bulbs in the right format, ending in .txt.

The code returns an error if the file doesn't exist, or is wrong.
If all bulbs cannot be lit up, the code writes a message saying that and goes further to evaluate how many bulbs can be lit up at the same time, this evaluation doesn't happen if all bulbs can be lit up at the same time.