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.

['1487', '8003', 'd', '7237', 'l', 'y', '2749', 'e', '9685', '2825', 'z', '7743', 'r', '9617', 'w', '4323', '2173', '8419', '2831', '8923', 'l', '2985', '303', 'y', '9409', 'i', 'h', 'e']
d, e, h, i, l, r, w, y, z

['a', 'a', 'b']
a, b

['5463', 'n', 'b', '3453', '191', '7601', 'e', 'x', '8231', 'o', 'k', 'p', 'u', '6933']

b, e, k, n, o, p, u, x