Solve as fast as possible i will upvote

CFG Design (6.5 points) Design a context-free grammar for the following language. Use S as the start variable. Explain your CFG in brief (in not more than 3 sentences). L = {w {a,b,c}* : w = aPb9c", p, q, r > 0, p=2r +1,q is divisible by 3}