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]: ['7989', '6897', 'o', 'v', '5687', '2933', 'w', '8207', 'y', 's', 'w', '3013', 'h']
[EX A]: h, o, s, v, w, y

[EX Q]: ['t', 's', 'q', 'i', '3285', '3761', '6603', 'p', '3587', '4885', 'w', '2341', '5159', 'l', 'z', '4775', '1237', 'p', '9341', '5847', 'b', 'j', '3859', 'd', 'b', '8811', 'f', '5891', '9975', '9799', 'c', 'e', 'd', '3325', '441', '1891', '4387', '6139']
[EX A]:
b, c, d, e, f, i, j, l, p, q, s, t, w, z