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.

Q: ['v', 'l', 'v', '7673', '8975', 'u', '2471', '4151', '3615', '1139', 'i', 'z', '8833', 'v', '341', 'l', 'n', 'l', 'd', '9207', '1861', '3901', 'a']

A: a, d, i, l, n, u, v, z
****
Q: ['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']

A: c, d, e, g, i, j, l, p, q, t, u
****
Q: ['2995', 'a', '6163', '6093', '4489', 'u', 'd', '8863', '5249', '5637', '7121', 'i', 'g', '6569', '9659', '3985', 'j', 'q', '8347', 'q', '5293', '2529', 'y', '741', 't', '3889', '385', 'j', 'b', '201', 'q', '7723', '5845', '3343', '8401', 'p', 'f']

A:
a, b, d, f, g, i, j, p, q, t, u, y
****