In \(m \times n\) Cram (see Exercise 1.4), a rectangular board of \(m \times n\) squares is given. The two players alternately place a domino either horizontally or vertically on two unoccupied adjacent squares, which then become occupied. The last player to be able to place a domino wins.

(a) Find the Nim value (size of the equivalent Nim heap) of \(2 \times 3 \mathrm{Cram}\).

(b) Find all winning moves, if any, for the game sum of a \(2 \times 3\) Cram game and a \(1 \times 4\) Cram game