1. Given a 7*9 grid with distinguishable (e.g. numbered) tokens on each square.
2. Move each one of the tokens to a neighboring place (horizontally, vertically-but not diagonally).
3. Evaluate the number of possible distinct solutions.
Remember: each token has to arrive to a square occupied initially by its neighbor.
4. Please submit the final answer and the amount of time spent to get it.