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]: ['1595', '2915', 'o', 't', 'c', 'h', '3969', '5407']
[EX A]: c, h, o, t

[EX Q]: ['s', '6723', 'l', '1573', '1129', 'n', '4277', '5003', 'y', '7563', 'c', '6747', '3105', 's', '3593', '8417', '8253', '4157', 'w', 'f', 'z', 'd', '9685', '1033', 'h', '4893', 't', 'j', '6821', 'z', 'a', 'u', '591', 'o', '1087', '2147', '1223', '2339', 'i', 'y', '9307', 'x', 'z', 'r', 'y']
[EX A]: a, c, d, f, h, i, j, l, n, o, r, s, t, u, w, x, y, z

[EX Q]: ['6427', '9435', 'u', '7241', 't', 'w', '651', 'z', 'k', '1199', 'd', 'u', '45', 'o', '7047', '4795', 'p', '7393', 'r', '1559', 'u', 'r', 'c', '9889', '4695', 'm', '3921', 'm', '2127', 'o', '5229', 'v', 'd']
[EX A]:
c, d, k, m, o, p, r, t, u, v, w, z