Here's a Christmas present for you. It's a Sudoku. And in keeping with Christmas present tradition you'll need to assemble it first yourself before you can solve it. We are confident you can follow the simple instructions.
We are also sure we left those instructions around here somewhere.
Anyway here's the third and final step:
S34 MN.PQR S138 3W.XYZ
M = C7 + E9 – I1
N = F3 + C4 – E7
P = B2 + G7 – A1
Q = G1 + H6 – B4
R = E9 + A1 – B4
W = D4 + G9 – C6
X = I9 + D3 – E8
Y = F8 + B5 – H1
Z = H6 + A5 – E2
Oh look, it seems that after a year of looking we have found the instructions after all. It just took a while. And here they are.
Merry Christmas (or seasonal holiday of your choice).
