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]: ['2775', '7507', 'c', '4417', '3449', 'y', 'z', 'e', 'f', '9515', '8555', '7269', '8353', '4239', '4347', '4479', '8645', '9925', 'o', 'h', 'o', '8641', 'y', '3251', '1191', 't', 'x', 'z', '7203', 'b', 'b', '7545', '7283', 'z', 'y', '8127', 'x', 'l', '6251', 'y']
[EX A]: b, c, e, f, h, l, o, t, x, y, z

[EX Q]: ['o', 'h', 'z', 'n', 'e', 'y', 't', '4371', 'm', '1059', '4853', '8529', 'l']
[EX A]: e, h, l, m, n, o, t, y, z

[EX Q]: ['8643', '9433', '583', 'g', '2571', 'j', 'f', '1617', '2663', '6829', 'p', '3803', '3543', '3757', 'i', 'o', '4117', '1357', 'e', '921', '3445', 'y', 'v', '1011', 'x', 'u']
[EX A]:
e, f, g, i, j, o, p, u, v, x, y