Matryoshka

Some rare Matryoshkas composed of seven dolls each were spread during the years and ended up distributed randomly among some antiquecollectors. Complete sets of rare Matryoshkas like these ones are worth a lot of money in the antiquities market. Groups of Matryoshkas from different sets, but with the same size have a good value too.

These collectors arranged a meeting to exchange dolls and try to reassemble the rare Matryoshkas. Obviously each collector wants to leave this meeting with the most valuable collection. But who will succeed?