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]: ['8495', 'p', 'j', 'm', 'n', '9115', '1183', 'r', 'r', '8735', 'a', 'i', 'k', 'p', '8927', 'r', '9283', '9563', 'g', '2503', 'h', '1091', '5257', 'a', '3061', '2835', 'l', 'w', 'j', '7617', '8793', '7463', 'h', '8467', '7337', 'b', '4655', 'd']
[EX A]: a, b, d, g, h, i, j, k, l, m, n, p, r, w

[EX Q]: ['1983', '1835', '6543', '6399', '4177', '9385', '7127', 'p', 'l', 'u', 'g', 't', '3423', 'g', 'b', 'l', '3133', '2429']
[EX A]: b, g, l, p, t, u

[EX Q]: ['2663', '6599', 'y', '5791', 'l', 'q', 'f', '329', '7845', 'k', '8381', '263', '3613', '5745', '8663', 'j', 't', 'o', '7699', 'b', 'b', 'l', 'g', 'b', '9425', 'o']
[EX A]:
b, f, g, j, k, l, o, q, t, y