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]: ['8975', '7199']
[EX A]: -1

[EX Q]: ['5345', 'f', '6605', 's', 'q', 'w', 'p', 'o', 's', 'u', 'i', '7339', '8379', 'h', '9547', 'b']
[EX A]: b, f, h, i, o, p, q, s, u, w

[EX Q]: ['9825', 'a', 'v', '9209', '1717', '1557', '8059', 'b', 'n', 'q', '1013', '4619', 'd', '7661', 'h', 'w', 'c', 'l', '6155', 's', '9923', '1219', 'k', 't', '3147', 'i', '2795', 'a', '775', 'x', 'u', '8179', 'h', 'i', '9207']
[EX A]:
a, b, c, d, h, i, k, l, n, q, s, t, u, v, w, x