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.

['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

['g', '8591', '4463', '2189', '7901', '1457', 'f', 'i', '9031', 'r', '5519', '3955', 'd', '2093', 'c', 'y', '6591', '6463', 'h', '4371', '111', 'p', '3221', '4185', 'p', '8761', 'w', 'p']
c, d, f, g, h, i, p, r, w, y

['991', 'v', 'i', '4915', '8401', 'h', '3039', '579', 'q', '2155', 't', 'm', '1323', 'p']

h, i, m, p, q, t, v