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]: ['i', '9215', 'n', 'p', '4815', '8757', 'm', '1755', 'c', 'z']
[EX A]: c, i, m, n, p, z

[EX Q]: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']
[EX A]: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y

[EX Q]: ['d', 'm', '3355', 'o', '7177', '4575', '7213', '8245', '4857', 'h', 'c', 'a', '581', '8439', 'b', '8961', '1533']
[EX A]:
a, b, c, d, h, m, o