Returns from functions. Imagine there is a girl Olya. All she can do is check whether the number is straight or not. You tell her a number, and she says “yes” if it’s straight, or “no” if it’s not straight.

She does nothing anymore.

And then one day you ask her a number, and she is silent and answers nothing. The cock. And all because she had removed the return operation. She checks the number, but she cannot answer, and you don’t know the answer.

Then she was sent to the institute of neurosurgery and sent a new return in exchange for the removed one. And she again began to answer "yes" or "no". And then the children understood how important it was that the function had a return and why it was needed and how bad it was to live without it.