Solve Jigsaw puzzle
Piece:
    data: Object
    neighbors: Set<Piece>

A B C D
E F G H
I J K L

    <--- 4 -->
   ^  A B C D
3  |  E F G H
   v  I J K L

Input: Set<Piece>
Output: int[2] (dimensions)
        int, int
        row, col

example input: {A, B, H, F, G, I, K)
where A: Piece(data="A", neighbors={B, E})