Tic-tac-toe game, in which you need to make two rows for "x", and for "o" make one row. A well-known game in which the draw algorithm was discovered for sure along with the invention. At the same time, it is one of the most ancient games in which they continue to compete until now. Archaeologists have discovered boards with lined tile fields used in ancient Egypt and dated to around 1300 BC. There were also chalk-marked fields dating back to the Roman Empire in the first century. The program algorithm was run in 1989 on the Soviet programmable calculator "MK-52", which is known for being taken on the Soyuz TM-7 space flight, where it was supposed to be used to calculate the landing trajectory in case of failure of the on-board computer. The game is played according to slightly modified rules. Since the advantage of the first move in tic-tac-toe is obvious, now it is necessary to draw up two adjacent (parallel anyway it will not work) rows. The computer needs to prevent this and make a regular series; at the same time, computer moves randomly, which is logical, since any meaningful move is guaranteed to deprive the chances of winning.