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.

['t', 'a', '2481', '2841', 'a', '2871', 'm', '4435', 'g', '8201', '4351', '9045', 'o']
a, g, m, o, t

['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']
e, l, n, p, q, r

['r', 'r', '1339', '6059', '9389', '1793', 'o', '3727', 'c', 'q', 'm', 'u', 'l', 'x', '8855', '7007', '829', '1435', 'h', 'g', '4735', 'u', 'o', '4287', 'v', 'v', '6163', '9341', '9519', '425', 'v', '9203']

c, g, h, l, m, o, q, r, u, v, x