The book "Eiler's characteristic" by Yuri Alexandrovich Shashkin is a fascinating and profound study that immerses the reader in the world of mathematics and its philosophy. The author, known for his work in graph theory and topology, offers a unique look at one of the most significant concepts in mathematics the Euler characterization. This book will be a real find both for students studying mathematics and for professionals seeking to expand their knowledge in this area. The book focuses on the Euler characteristic, which is an important tool in topology and geometry. Shashkin not only explains what it is, but also shows how this characteristic can be used to solve various problems related to shapes and spaces. He guides the reader through many examples and tasks, which makes the material not only accessible, but also fascinating. Readers will be able to see how Euler’s characterization is applied in a variety of fields, from architecture to computer science, from biology to physics. The book is addressed to a wide audience . It will be of interest to students and graduate students of mathematical and technical specialties, as well as teachers who are looking for new approaches to explaining complex topics. The Eulerian characterization will also attract the attention of mathematics enthusiasts who want to deepen their knowledge and understand how abstract concepts can find application in real life. In it will find something useful and those who are simply interested in science and want to expand their horizons. The topics raised in the book concern not only mathematics itself, but also philosophical issues related to its perception and application. Shashkin asks questions about how mathematics can describe the world around us, how it relates to art and nature. This makes the book not only a textbook, but also a philosophical reflection on the role of mathematics in our understanding of reality. Yuri Shashkin's style is distinguished by clarity and accessibility. He skillfully combines theory with practical examples, which allows the reader to easily absorb material. His other well-known works, such as Graph Theory: From Basics to Applications and Mathematics for All, also demonstrate his ability to explain complex concepts in simple and understandable language. In The Euler Characteristic, the author continues this tradition by focusing on the reader's interactivity and involvement. The book “Eiler’s characteristic” is not just a textbook, but a real guiding star in the world of mathematics. It inspires study and exploration, opens new horizons, and makes you think about how mathematics permeates all aspects of our lives. If you are looking for a book that will help you not only to master important mathematical concepts, but also to see their application in the real world, then the “Eiler characteristic” will be an excellent choice. Do not miss the opportunity to immerse yourself in this fascinating world, where mathematics and philosophy are intertwined, creating a unique picture of our understanding of the surrounding reality.