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:
['7561', 'r', '3419', 'k', 's', '5997', 'u', '6635', '7003', '8491', 'i', '9835', 'c', '8827', 'h', 'a', 'j', '7675', '1995', '1223']

Ex Output:
a, c, h, i, j, k, r, s, u


Ex Input:
['3191', '2655', '239', '2585', '3369', '7815', '5919', '8269', '5633', 'x', '8085', '2909', 'y', '2465', 'i', '1579', 'u', '2371', 'l', '1949', '51', 'e']

Ex Output:
e, i, l, u, x, y


Ex Input:
['7641', 'e', 'c', 'p', '9917', 'u', '7335', 's', 'b', 'l', '2437', '759', 'h', 's']

Ex Output:

b, c, e, h, l, p, s, u