7.5. Egor, Nikita, and Innokentiy took turns playing chess with each other (two play, one watches). After each game, the loser would give up their place at the board to the spectator (there were no draws). In the end, it turned out that Egor participated in 13 games, and Nikita in 27. How many games did Innokentiy play?
Answer: 14.

Solution: On the one hand, there were no fewer than 27 games. On the other hand, a player cannot skip two games in a row, meaning each player participates in at least every other game. Therefore, if there were at least 28 games, Egor would have participated in at least 14, which contradicts the condition. Thus, exactly 27 games were played, and Nikita participated in all of them. In 13 of these, his opponent was Egor, so in the remaining 14, it was Innokentiy, and this is the answer.

Criteria: Only the answer, answer with verification - 0 points.