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:
['f', 'a', 'r', '4009', 'k', 'a', 'g', '7725', 'v', 'b', '6705', 'a', '6583', '3159', 'c', 'w', 'x', 'h', '7625', 'p', 'y', '5645', 'k', 'r', 'j', '4175', 'r', '3103', '8631', '5999', 'p', 'g', 'h']

Ex Output:
a, b, c, f, g, h, j, k, p, r, v, w, x, y


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:
['s', '449', '4491', 'y', '2183', 'n', 'k', '9401', 'd', '3445', '6951', 'r', 'b', '8253', 'o', 'y', 'g', '8855', 'k', '8963', '3439', '6561', 'c', '6931', 'v', 'n']

Ex Output:

b, c, d, g, k, n, o, r, s, v, y