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 Input:
['c', '9125', '6049', '5201', 'v', '9311', 'q', '3305', 'l', 'q', '3387', '3647', 'x', '471', 'a', '5631', 't', '9679', '5423', '2569', 'w', 't', '6397', 'e', 'h', 'c', 'v', 'v']

Ex Output:
a, c, e, h, l, q, t, v, w, x


Ex Input:
['7997', 'm']

Ex Output:
m


Ex Input:
['3111', 'g', 'k', 'x', 'r', 'c', '3081', '5013', 'x', '8779', 'k', 't', '4043', '467', '5335']

Ex Output:

c, g, k, r, t, x