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.

[Q]: ['3147', '9807', '5313', '6311', '737', '1555', '5803', '3437', '5665', '3973', 'o', 'f', '7871', '1721', '7833', '2933', 'b', 'b', 'n', 'm', 'k']
[A]: b, f, k, m, n, o


[Q]: ['7071', 'h', '837', 'z', 'c', '2217', 'c', '6341', '6607', 'g', '3569', 'a', 'h', 't', 'b', 'f', 'g', 'f', 'l', 'b', 'x', 'o', 'r', '8949', '8071', '1507', 'v']
[A]: a, b, c, f, g, h, l, o, r, t, v, x, z


[Q]: ['4651', 'd', 'h', '1311', '9049', 'w', '7547', '5165', 'q', 'r', '3737', 'g', 'i', 'e', '7255', 's', '3229', 't', 'g', 'r', 'a', '2739', 'l', '179', '97', '5723', '6339', 'e', '3521', '8117', '1019', '2701', '1531', 'w', '3869', '5397', '6975', 'r', '3573', '2521', '789', 'n']
[A]:
a, d, e, g, h, i, l, n, q, r, s, t, w