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]: ['g', 'u', 'q', '1375', '9491', 't', 'w', 'c', 'v', 'y', '3169', '1607']
[EX A]: c, g, q, t, u, v, w, y

[EX Q]: ['8319', 'f', 'w', 'w', 'v', '6521', '4503', 'b', 's', 'b', '9651', 'k', '4635', '2195', '7537', '6839', 'i', 'd', 'b', '205', 'q', '7333', 'q', '5129', '4921', 's']
[EX A]: b, d, f, i, k, q, s, v, w

[EX Q]: ['k', '3667', 'e', 'z', '8691', '8407', '9885', 'l', 'f', '6519', 'f', 'i', 'l', '527', 'p', '7693', '7063', '6199', '8411', 'r', '9979', 'c', '9599', 'x', 'l', 'j', 'y', '8431']
[EX A]:
c, e, f, i, j, k, l, p, r, x, y, z