algorithms of recommender systems are discussed by sergei nikolenko, researcher at the center, associater of st. petersburg university, head of the laboratory of the st. petersburg department of the mathematical institute of the ras. what is the peculiarity of his work explaining on cats at the moment when his pet is watching the interview, you cannot write a program manually that would distinguish cats in a photo, but you can collect a million photos of cats and write a program that, based on this million, will learn to answer their meeting . here, therefore, somewhere in the nineties, machine learning can already be said, everything for the present personally with artificial intelligence is few in the sections of artificial intelligence that would not be about machines, learning by and large, sergey teaches artificial intelligence to learn. at the same time, he does not forget to learn new things, such as music. music of course there is some kind of mathematics there, what the ancient greeks meant by this, that the length of the strings must clearly correspond to each other and be in s