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.

[EX Q]: ['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']
[EX A]: g, h, k, l, o, t, y, z

[EX Q]: ['z', '2519', '4799', '4715', '7165', 'r', 'r', 'l', 'n', '6925', '8935', '9795', '5489', 'v', 'u', '6527', '2241', 'u', 'c', 'w', '9755', 'w', '9823', 'g']
[EX A]: c, g, l, n, r, u, v, w, z

[EX Q]: ['1497', 'b', 'g', '8523', '8179', '151', '1075', 'z', 'y', '3721']
[EX A]:
b, g, y, z

