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.

['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']
f, h, j, n, u, w

['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']
d, f, h, i, j, l, p, q, s, u, x, y, z

['u', '2089', '4333', 'c', '5219', 'i', '7529', 't', 'v', '1075', 'v', 'q', 'r', '6091', '7401', '8261', '4109', 'f', 'f', 'b', '8781', '5347', 't', '7703', '6779', '7267', '6325', 'q', 't', 'p', '2793', 'o', '2297']

b, c, f, i, o, p, q, r, t, u, v