The beginning of the computer science lesson, the students did not sit still, making noise and running around the class, waiting for the teacher not to arrive, but alas, unfortunately for the children, the teacher was announced and entered the room a little late, just a couple of minutes. Clapping his hands to attract attention, Shalnark walked to his table.

- I don’t want to interrupt your joy, but I suggest starting the lesson. Where did we leave off? - asked the computer science teacher turning on his school computer.