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]: ['q', 'g', 's', 'g', 'z', '987', '777']
[EX A]: g, q, s, z

[EX Q]: ['7065', 'f', 'k', 'i', 'd', '8291', 'z', 'e', 'q', '5345', 'h', '3397', 's', '5355', 's', '9033', 'e', '5241', '5285', 'm', 'h', 'i', 'n', '6471', '3365', 'f', 'r', '6145', 't', '4869']
[EX A]: d, e, f, h, i, k, m, n, q, r, s, t, z

[EX Q]: ['l', '5927', '3575', 'j', '9873', 'h', 'u', '7737', 'd', '2845', 'e', '7415', '9897', '9839', '6401', 'a', '4501', 'v', '1183', '9991', 'v', 'l', 'w', '7031', '1795', '6265', 'm', '9235', 'n']
[EX A]:
a, d, e, h, j, l, m, n, u, v, w