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.

['i', 's', 'f', 'i', '2293', '245', '4983', 'h', 'h', '6203', '8703', '1613', 'h', 'o', '3635', '8069', '2829', '1939', 'u', 'm', '5305', 'n', 'k', '9367', 'u']
f, h, i, k, m, n, o, s, u

['895', '2049', '8839', '1773', 'v', '467']
v

['5163', '1413', 'x', '4915', 'y', '6895', 'd', 'q', '3889', 'g', '7327', 'b', 'l', '9647', 'f', '2197', 'h', '9183', '861', 'f', 'z']

b, d, f, g, h, l, q, x, y, z

