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.

['k', 'z', '303', 'a', 'f', 'q', 'i', '1475', '3453', 'd', 'w', '4037', 'z', 'h', 'k', '3547', '1561']
a, d, f, h, i, k, q, w, z

['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']
i, j, o, w

['7347', '851', '6737', 'q', '3023', '863', '1989', '2005', '3829', 'b', 'j', '599', '8397']

b, j, q