3. (10 points) Recall the recursively defined set S of all RNA strands over the bases in the set B= {A,C,G,U} : Exercise: Recursively define a function AplusG from the set S to the set N that computes the number of Gs plus the number of As. For example, AplusG(AAGGUCAUC) =5 and AplusG(GUGGCG) =4 Your function needs to follow the format of a recursive function. Namely, Basis Step: > Recursive Step: >