"Combinatorics. Workshop on problem solving: A textbook is not just a textbook, but a real guide to the fascinating world of mathematical logic, analysis and creativity, created by a team of experienced authors who devoted their lives to popularization and in-depth study of combinatorics. This book is intended for those who want not only to master the theoretical foundations, but also to learn how to apply them in practice, solving a variety of problems that cause interest and require non-standard thinking. The focus of this manual is the practical side of combinatorics, which often seems difficult and inaccessible to beginners. The authors suggest that the reader immerse himself in the world of tasks, starting with simple exercises and gradually moving to more complex ones, revealing the secrets of effective methods of solving. Each chapter is filled with examples, detailed solutions and tips that help to understand how to apply theoretical knowledge in real-world situations. This approach makes the book especially valuable for students, faculty and anyone who wants to develop analytical abilities and logical thinking. The Combinatorics . Workshop on problem solving" is perfect for high school students, students, as well as for those who are preparing for exams in mathematics, olympiads and competitions . Its content is interesting and useful for both beginners and those who already have basic knowledge, but want to deepen their skills. This workshop will become an indispensable assistant for teachers looking for additional materials for classes, and for independent students seeking self-development. The peculiarity of this manual is its structured approach to solving problems. The authors not only explain the theory, but also teach to think logically, look for non-standard solutions, apply different methods and approaches. The book raises important topics such as permutations, combinations, placements, principles of inclusion and exclusion, and more complex sections related to graphs, trees, and combinatorial structures. Each topic is accompanied by practical tasks that help to consolidate the material and develop analytical thinking skills. The style of presentation of the authors is clear and accessible, which makes the book understandable even for those who are just beginning to get acquainted with combinatorics. At the same time, it does not lose scientific rigor and depth, which allows it to be used as a teaching tool for in-depth study of the subject. The authors, known for their work in the field of mathematical education and popularization of science, are able to interest the reader, turning complex concepts into an exciting adventure. If you are looking for a book that will help you not only understand the basic principles of combinatorics, but also learn how to solve complex problems, Workshop on Problem Solving" will become your reliable companion. This manual is an excellent choice for those who want to develop logical thinking, prepare for the Olympics or simply expand their knowledge in the field of mathematics. Due to its practical bias and rich material, it deservedly ranks among the best textbooks on combinatorics in Russian. So, if you are interested in mathematics, love solving puzzles and want to learn to see patterns where others see chaos, this book will be a real discovery for you. "Combinatorics. Workshop on problem solving" is not only a textbook, but also a source of inspiration for those who seek to develop intellectual abilities and love to overcome intellectual challenges. The authors have created a unique resource that will help you become more confident in your knowledge and skills, as well as open new horizons in the world of mathematics.