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]: ['887', 'p', '3819', '2727', '1407', 'b', 'n', '737', 'd', 'w', 'q', '6877']
[EX A]: b, d, n, p, q, w

[EX Q]: ['p', 'g', 'q', 'e', '8045', '9999', '9555', '7995', '7195', 'z', 't', '5223', '3699', 'i', '4797', '3817', 'x', 'y', 'w', 'o', '8915', '7803', 'n', '1117', 'c', '9647', 'p', 'e', '9669', '4845', '9255', '4545', '3693', '6871', 'w', '4327', '3285', 'k', 'f', 'x', 'i', 'b', '5967', '6601']
[EX A]: b, c, e, f, g, i, k, n, o, p, q, t, w, x, y, z

[EX Q]: ['c', '4873', '7965', '7173', 'z', '2161', '473', '8355', 'u', 'p', '7219', 'z', '4395', '7725', '1905', 't', '5987', '5855', '6013', 'w', 'g', '5245', 'k', '3191', 'r', '5379', 'z', '9247', 'e', 's', '8161', 's', 'v', '4435', '567', 'o']
[EX A]:
c, e, g, k, o, p, r, s, t, u, v, w, z