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]: ['5075', '9169', '4659', '7605']
[EX A]: -1

[EX Q]: ['q', '9033', 'p', 'z', '1743', '247', '967', '445', '9849', 'f', '9113', 'b', 'g', '6041', 'j', '927', 'i', 'p', '6821', 'q', '6701', 'f', 'j', 'o', 'y', 'c', '7981', 'b']
[EX A]: b, c, f, g, i, j, o, p, q, y, z

[EX Q]: ['3561', 'b', '2795', '5823', '9917', '3597', 'h', 'm', '3645', 'p', '8923', '1757', '641', '1879', '7481', 'g', 's', 'v', 'o', 'y', 'o', '8771', '9519', 'z', 'd', 'v', 'q']
[EX A]:
b, d, g, h, m, o, p, q, s, v, y, z