Lisa, a brilliant mathematician, makes a living by cleaning. She does not understand the motives and actions of people very well, but things that have lived with people are a different matter: she instantly analyzes their characteristics, learning about their owners even what she would prefer not to know. Unlike people, things never lie, Lisa is sure. But one day she will be forced to doubt this. This book can be read in different ways: as an exciting thriller, as a novel of education and growing up, as a philosophical parable, and even as a discussion about the unity and opposition of music and mathematics. However, no matter how you read it, fragile, but stubborn and fearless Lisa will forever take a place in your heart. Contains obscene language. Publishing design is preserved in PDF A4 format.