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.

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

['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']
f, j, n, s, u, w

['247', 'h', 'n', 'u', '3093']

h, n, u