If X has Poisson distribution with the mean of 2.3, Y has Negative Binomial

distribution with p = 0.62 and k = 4, and X and Y are independent,

find Pr(X + Y > 5).

Hint: Use probability generating function.

I would usually fill in on what I have tried so far, but even with the hint here I can't seem to get started. Any help is appreciated