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]: ['z', '8407', 'y', 'h', '1377', '3511', '1449', 'z', '3991', 'n', 'x', 't', 'h', '6389', '8049', '6091', '7787', 'p', 'l', '5815', 'k', 'e', 's', 'a', '9491', 'w', '1909', '4801', '4725', 'i']
[EX A]: a, e, h, i, k, l, n, p, s, t, w, x, y, z

[EX Q]: ['s', 'u']
[EX A]: s, u

[EX Q]: ['691', '4087', 'w', 'j', '5235', 'j', 't', '8431', 'p', 't', 'h', '6465', '1303', '7387', 'a', '2931', 't', '9387', '9469', '6159', '9067', 'w', '3347', 'k', 'e', '8797', '2731', '3643', 'n', '3025', '3517', '4017', 'm', 'f', '2901', 'q', 'l', 'a']
[EX A]:
a, e, f, h, j, k, l, m, n, p, q, t, w