Dominos

Dominos (Dominosa, Domino Hunt) is a logic puzzle game. Separate the dominoes, formed into a rectangle, into individual dominoes.

Rules: The grid is divided into dominoes (regions consisting of exactly two squares) along the grid lines.
Each domino exists exactly once: 1-1, 0-1, etc. up to N-N; no distinction is made between X-Y and Y-X (e.g., 1-3 and 3-1).