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]: ['t', 'a', '2481', '2841', 'a', '2871', 'm', '4435', 'g', '8201', '4351', '9045', 'o']
[EX A]: a, g, m, o, t

[EX Q]: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']
[EX A]: a, h, m, n, p, s, v, w, y

[EX Q]: ['3057', 'a', 'a', '2321', 'k', '8553', '2163', 's', '4205', '6195', '4963', 'e', '5671', '3803', '5119', 'a', 'b', '3389', '9035', 'q', '2853', 's', '619', '2399', '9551', 'i', 'z', 'g', 'c', '3883', 'n', '6599']
[EX A]:
a, b, c, e, g, i, k, n, q, s, z