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:
['u', '4731', 'l', 'p', '1997', '601', 'n', 'l', 'p', '211', '7355', '6537', 'w', 'x', '1741', '8145', '3689', 'm', 'y', '6945']

Ex Output:
l, m, n, p, u, w, x, y


Ex Input:
['g', 'x', 'l', 'e', 'd', '1345', '1763', 'm', 'c', '2057', 's', 'a', '4127', 'y', 'h', '8581', 'o', '9203', '4761', 'd', 'u', 'n']

Ex Output:
a, c, d, e, g, h, l, m, n, o, s, u, x, y


Ex Input:
['y', 'w', '2019', '159', 'v', '9555', 'v', 'a', 'l', 's', 'i', 'o', 'q', 'b', 'c', 'j', 'k', '525', '4995', 'n', '1805', '4693', '3495', '6333', '9585', 'm', 'l', '6099', 'l', '2679', 'z', 'w', '5557', 'l', 'z', '4575', '3991']

Ex Output:

a, b, c, i, j, k, l, m, n, o, q, s, v, w, y, z