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:
['1627', 'r', '2429', 'b', '4451', 's', 'k', 'm', '269', 'l', '709', 's', 'q', '985', 'x', 'j', 'k', 'k', '6603', 'v', '9497', '477', '5803', 'c', 't', 'f', '3189', '6419', '8561', '5709', 'u', 'z', '5717', '9711', 'w', 'y', 'm', 'v']

Ex Output:
b, c, f, j, k, l, m, q, r, s, t, u, v, w, x, y, z


Ex Input:
['1657', 'u', '1849', '425', 'v', '6435', 'j', '2985', '921', '9553', '2621', 'i', '7103', 'd', '8563', 'l', 'b', '6727', '4235', 'n', '8021', 'd', 'z', '437', 'm', '5695', 't', '3421', 'e', 'a', '2941', '791', '1417', '9247', 'h']

Ex Output:
a, b, d, e, h, i, j, l, m, n, t, u, v, z


Ex Input:
['a', 'u', 'l', '1255', '6529', 'p', '6915', 'm', '7099', '5261', 'w', '523', 't', '4897', 'j', 't', 'o', 'd', 'v']

Ex Output:

a, d, j, l, m, o, p, t, u, v, w