In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.

['s', 'u']
s, u

['5785', 'c', 'f', '7087', 'd', '9225', 'm', 'g', '4639', '7165', '3445', '3813', 'p', 'i', '719', 's', 'g', '6423', '9563', 'w', 'm', '8659', '8809', '4105', '3923', '465', '5637', '5547', 'h', 'v', '9453', '4009']
c, d, f, g, h, i, m, p, s, v, w

['5297', 'j', 'u', 'q', 'v', 'x', '3295', 'g', '9957', '2683', '3']

g, j, q, u, v, x