[AlphaWice]

This is such an easy problem.

Work with one line only: if we know the probability for one line, we are done.

Let A, B be the probability of "hues", "hews" occuring in that line. P(A union B) = P(A) + P(B) - P(A intersection B)
where all of them are easy to calculate.

Here I haven't actually calculated anything, but it is very easy to do, and requires only grade 11 math.