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]: ['c', 'a', 'p', 'p', '4203', '1587', '2953', '9809', '99', '5821', 't', 'i', '4213', '1809', 's', 'l', 'i', 'b', '9233', '3983', '7713', '1807', 'k', 'f', '7825', '5491', 'o', '1347', 'u', 'h', '3967', 'u', 'g', '6775', '1069', '9211', 'i', '3369', 'r']
[EX A]: a, b, c, f, g, h, i, k, l, o, p, r, s, t, u

[EX Q]: ['z', 'm', 'n', 'u', '9159', '7931', '5401', '1383', '8195', 't', 'x', 'q', 'r', '2535', 's', 'j', 'c', '8123', '2429', '5581', 'k', 'c', 't', 'i', 'm', 'o', 't', 'q', '4819', 't', '1649', 'r', 'y', 'z', '8813', '7451', '199', 'o', 'x', 's', 's', '6747']
[EX A]: c, i, j, k, m, n, o, q, r, s, t, u, x, y, z

[EX Q]: ['6779', 'q', 'h', 's', 'z', '7723', 't', '6743', '1277', 'y', 'w', 'a', '105', '5765', '8183', 'x', 'u', '567', 'i', 'b', '2797', 'v', 'n', '4201', '209', 'g', '5671', '9027', '5', 'x', '7399', '7635', 'q', '8637', '4615', 'o']
[EX A]:
a, b, g, h, i, n, o, q, s, t, u, v, w, x, y, z