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:
['4371', '9499', 'e', 'w', '9969', '8367', '2897', '1745', 'i', '7049', '9773', 'h', '9649', 'u', '4673', '8513', '8547', 'z', '1995', '7739', '2215', '171', 'c', '7527', '2479', 't', '5223', 'p', '2313', '3243', '2281', 'r', 'c']

Ex Output:
c, e, h, i, p, r, t, u, w, z


Ex Input:
['7071', 'h', '837', 'z', 'c', '2217', 'c', '6341', '6607', 'g', '3569', 'a', 'h', 't', 'b', 'f', 'g', 'f', 'l', 'b', 'x', 'o', 'r', '8949', '8071', '1507', 'v']

Ex Output:
a, b, c, f, g, h, l, o, r, t, v, x, z


Ex Input:
['g', 'l', '4501', '9115', '5029', '6093', '8695', '481', 'p', 'p', 'n', '3673', '8255', 'b', '1553', 'm', 'v', 'k', '3367', 'u', 's', '8319']

Ex Output:

b, g, k, l, m, n, p, s, u, v