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:
['5431', 'o', 'u', 'l', 'f', 'd', 'r', '1479', '9357', 's', 'v', '6399', 'b', '7937', 't', '8497', 'r', '131', 'h', 'c', 'v', '8879', 'k', 'r', '4687', 'l', '1065', 'r', 'w', 'l', '3305', '461', 'q', 'h', 'b', 'e', 'e', 'w', '5999']

Ex Output:
b, c, d, e, f, h, k, l, o, q, r, s, t, u, v, w


Ex Input:
['1799', '6409', '9257', '5923', 'm', 'j', '2565', '715']

Ex Output:
j, m


Ex Input:
['1927', 'f', 'z', 'i', '6763', 'c', '9667', '4461', '9889', 'e', 'm', 'y', '6711', 'i', '7947', '7787', 'k', '2581', 'u', 'p', '485', '3859', '9407', '5289', '6351', 'w', '5625', '2915', 'a', 'w', 'n', '2125', '9075', '8023', '9133', '6469', '5963', 'b', 'i', '1455']

Ex Output:

a, b, c, e, f, i, k, m, n, p, u, w, y, z