Please provide answer with proof and answer only if you know what it is.

So, Σ = {a, b, c, d, e} 
Find a non context free language F on Σ  such that all symbols appear at least in one of the strings in F and a non regular language context free language K such that F ∪ K is context free. Find a prove of "F is non context free, K is context free and F ∪ K is context free"