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:
['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']

Ex Output:
c, e, u


Ex Input:
['1653', '3177', 'b', '2785', '2515', 'd', '5513', '5599', '2947', 'v', '2771', '5697', '2913', '4161', '5939', '2655', '6787', '9851', 'q', '3199', 'x', '1305', '9423', '9117', '4821', 'j', '7963', 'i', 's', '469', 'r', 'w']

Ex Output:
b, d, i, j, q, r, s, v, w, x


Ex Input:
['u', '73', '8837', '6701', '1927', '8825', '8079', '7251', 'o', '2763', 'p', 't', '7055', 'h', '6183', '1625', '2795']

Ex Output:

h, o, p, t, u