A logical puzzle, the well-known and familiar game "2048", but slightly modified.
The player's task is to combine adjacent cells with the same numbers in as large
a chain as possible. The main feature is that it is possible to combine numbers of a higher denomination
than the original chain, but not less. For example, by connecting two twos, you can continue
the chain with the same twos. Or you can switch to fours and so on until there are
no necessary neighboring cells left.