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]: ['u', '4021', 'u', 'd', 'j', 'p', 'i', 'z', '3223', 'f', 's', 'l', 'p', 'd', '5031', '1059', '7875', '2097', 'q', 'i', '8813', '2017', 'h', 'l', 'y', '57', '1561', 'f', 'j', 'z', '1901', 'u', 'j', 'x', '6561', '9239', '3333', '8793', '4915', '5821', 'h', 'f', '765', 'x']
[EX A]: d, f, h, i, j, l, p, q, s, u, x, y, z

[EX Q]: ['3797', '6117', 'x']
[EX A]: x

[EX Q]: ['p', 'i', 'p', 'x', '6641', 't', 'x', '9969', 'h', 'f', 'b', 'g', '629', '9975', '9203', 't']
[EX A]:
b, f, g, h, i, p, t, x