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.

['6575', '2057', '2135', '6259', '7741', '4919', '7461', 'v', '401', 'h', 'u', '2391', '2181', 'y', '9273', 'd', 'b', 's', '7993', '9323', 'b', '7015']
b, d, h, s, u, v, y

['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']
a, e, i, n, p, q, r, s, t, u, x

['y', '8647', '1619', 'f', 'h', 'b', 'z', '7653', 'i', 's', '6763', '6511', '9933', '5043', 'o', 'o', 'k', '6573', 'e', '6089', '7663', 'u', '4055', '1529', '7785', '5755', 'g', 'n', 'u', 'q', 'd', '721', 'g', 'h', 'n', 'f']

b, d, e, f, g, h, i, k, n, o, q, s, u, y, z