2. Anton, Boris, Vasya, and Grisha met. It is known that each of them is either from the tribe of knights (who always tell the truth) or from the tribe of liars (who always lie). Anton said that he and Grisha are from the same tribe. Boris and Vasya called each other knights. And Grisha claimed that there are no more than two knights among them. From which tribe is Boris?
Answer: Borya is a liar.

Solution. Whoever Anton might be, from his statement it follows that Grisha is a knight. The statements of Borya and Vasya mean that they are from the same tribe. Since Grisha is truthful, Borya and Vasya cannot be knights. Therefore, they are liars.

Grading. Full solution: 12 points. If only one of the two possible distribution options among the tribes is provided, then 3 points.