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]: ['7591', '7521', 'm', '1429', 'x']
[EX A]: m, x

[EX Q]: ['h', 'v', '1263', 'y', '3299', 'd', 'a', 'h', 's', '2007', '7597', '1015', 'k', '6643', '6959', 'g', 'u', 'd', '5737', 'n', 'z', 'y', 'b', 'g', '9059', '7349', 'j', 'w', 'i', 'z', 'p', '5809', 'x', '4421', 'g', '6399', '3965']
[EX A]: a, b, d, g, h, i, j, k, n, p, s, u, v, w, x, y, z

[EX Q]: ['1963', 'g', 'x', '6077', '8889', 'a', 'r', 'z', '3655', '8555', '2495', '4079', 'c', '6927', '6537', 't', 'o', '373', 'a', '9181', '3995', '4581', '4723', 'e']
[EX A]:
a, c, e, g, o, r, t, x, z