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.

Input: Consider Input: ['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']

Output: p, q, y


Input: Consider Input: ['3035', 'f', 'k', 'e', '3023', 'p', '9667', '5277', '4757', '8433', 'g', '1399', '7721', 'n', 'p', '7469', '7581', '5679', 'g', 'q']

Output: e, f, g, k, n, p, q


Input: Consider Input: ['509', 'm', '2567', 'b', 'k', 'f', '9863', '5431', '5763', 'b', '1507', 'v', 'h', 'u', 'm', 'j', 'u', 'k', 'f', '6681', '3085', '7845', '959', 'u', '149']


Output: b, f, h, j, k, m, u, v