The animated film is based on a poem by Vladimir Mayakovsky, in which a boy and a girl, brother and sister Knopochkins, discussed the choice of their future profession. Both the boy and the girl wanted to benefit people, but long debated about what kind of profession is still more important. In the end, they came to the conclusion that each of them is good in its own way, and if there was not one of them, then there will be no progress, no health, no good life in the future.