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]: ['8357', 'x', 'w', '287', 'z', '2733', '1757', 'w', 'g', '1393', '7201', '4931', 'k', '5185', 'x', '6313', '2255', 'z', 'v', '3593', '6191', '4423', 'm', 'k', '3209', '3559', 'c', 'n', 'm', '5461', '2997', '235', '4045', '6597', 'v', 'e', 'p', 'c', 'k', 'd', '5529', '6241', 'u', 'f', '8067']
[EX A]: c, d, e, f, g, k, m, n, p, u, v, w, x, z

[EX Q]: ['749', 'r', 'a', 's', 't', '5905', 'm', 'd', '8437', '4583']
[EX A]: a, d, m, r, s, t

[EX Q]: ['2969', '1977', 'k', 'i', '8353', 'r', 'n', '2673', '2713', 'e', '3411', 'z', '9153', '7263', '1985', 'r', 'o', '7279', '2113', '6259', '5463', 'j', 'a']
[EX A]:
a, e, i, j, k, n, o, r, z