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]: ['2329', 'i']
[EX A]: i

[EX Q]: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']
[EX A]: j, l, n, q, r, s, y

[EX Q]: ['q', 's', 'l', '1225', '7813', 'v', 'x', '8001', 'z', 'r', 'm', '6509', '3773', '7251', 'l', 'f', 'n', 'w', 'e', '2397', '7767']
[EX A]:
e, f, l, m, n, q, r, s, v, w, x, z