Determine whether language is regular using pumping lemma.

The alphabet is = = {a,b,c,d} Is the below language L regular or nonregular? If Lis regular give a regular expression that denotes it. If L is non-regular, prove that it is non-regular using the pumping lemma. L = {a' b2k c d? | i > 1,k > 1, m > 1,2 > 1} U{c+639 22x | x > 1, y > 1}