The letters W, X, Y and Z are to appear twice in every row and column and once in every 2x2 box.
From the given starters, can you finish the puzzle?
X | | | | W | | W | | |
| W | Y | | | Y | | | |
| | | | | | | Z | |
| X | X | | | W | | | |
Z | | W | | W | | | Z | |
| | | Y | | | | | |
| | | | | | | Y | |
| X | W | | | Y | X | | |
The completed arrangement is as follows:
x..y z..x w..z w..y
z..w y..w x..y z..x
w..z y..w y..x x..z
y..x x..z z..w y..w
z..y w..x w..x y..z
x..w z...y y..z w..x
w..z x..y x..w z..y
y..x w..z z..y x..w