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.

[Q]: ['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']
[A]: b, l, o, q, u, v, w


[Q]: ['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']
[A]: c, d, e, f, l, n, p, q, t, u, v, y


[Q]: ['q', '5581', 'c', '5129', '9509', '3153', 'n', '3053', '7093', '5043', '9515', '8261', 'r', '2117', 'k', '9829', 's', '5709', 'a', 'j', 'z', '833', 'v', '6683', 'k', '5027', 'u', 'n', '8417', 'v', '6289', 'd', '2415', 'b', '9635', 'y', 'w']
[A]:
a, b, c, d, j, k, n, q, r, s, u, v, w, y, z