The idea is to replace all the pieces back on the board according to the following rules:
1) No symbol may be put on the same symbol (i.e. not sheep on sheep).
2) No symbol may be laid beside the same symbol, neither horizontally, vertically, nor diagonally.
3) If a piece is laid down, the covered symbol is no longer useable.
4) Once a piece is laid down, it may not be removed.
5) If there is no further possibility to lay, the puzzle starts from the beginning.