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:
['1595', '2915', 'o', 't', 'c', 'h', '3969', '5407']

Ex Output:
c, h, o, t


Ex Input:
['u', 'w', '401', 't', 'g', 'h', 'g', '8073', '9597', '1347', '7835', '5007', '977', 'p', '7679', 'b', '4883', '4931', '999', 'r', '1181', 'x', '2063', 'l', 'w', 'i', 'l', 'x', 'i', '9057', '5007', 'w', '743', '1635', 'y', 'f', '9227', 'z', '5227', 'd', '7129', 'k', '7657']

Ex Output:
b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z


Ex Input:
['2145', 'n', 'f', 'k', '525', '5963', '5521', 'n', '6061', 'i', '6449', '9481', 'e', 'p', 'n', 'w', 'g', 'k', '323', '8483', '7305', 'k', '179', 'h', 'z', '2065', 'p', '9185', '1083', '5543', 'j', '6897', 'm', 'u', 'h', 'o', 'o']

Ex Output:

e, f, g, h, i, j, k, m, n, o, p, u, w, z