The genius of mathematics Mikhail Nefedov teaches probability theory and mathematical statistics at the university. He remembers everything he has ever heard, seen or read. Mikhail learns that his teenage son has a dangerous genetic disease, the treatment of which will require a multimillion-dollar sum. After selling the apartment, Nefedov makes a perfectly calculated bet on a local football league match, but loses. He couldn't have made a mistake, which means there is an unaccounted variable in the equation. And this is an underground betting business where the results of games are rigged to extract illegal income. Mikhail calculates the organizers of the shadow business and demands his winnings from them. This is how the university teacher's war with the betting mafia begins.
During the swimming training camp, coach Sofia and her husband, coach Trofim, take their niece, an orphan, to raise. Anya shows hope, but does not talk after the death of her parents, which becomes the subject of harassment among other athletes. By standing up for Dima, one of the guys on the team, she gets her first real friend. In parallel, a chain of irreversible consequences begins, which can destroy the relationship of Trofim and Sophia.
The unifying beginning of all the stories are their characters – they are all teenagers just entering adulthood. The theme of socio-psychological adaptation in the big world, the search for oneself and the difficulties of communication runs through all the films. These young people are ready to desperately run on thin ice, look for their favorite toy in a huge city dump, run away from their parents in their van, build a model of a dream house day after day, sit for hours in the pouring rain. In short, they are all learning to live.