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.

[Q]: ['t', 't', 'p', '3245', 'x', 'g', 'i', 'u', '2599', '8613', 't', 'v', 'p', '5635', 'y', '9567', '5193', '8617', 'q', 'f']
[A]: f, g, i, p, q, t, u, v, x, y


[Q]: ['w', 'n', '729', '2491', 'n', 'x', '915', '1869', 'z', '8491', '9947', '561', '829', 'n', 't', 'i']
[A]: i, n, t, w, x, z


[Q]: ['d', 'z', '2685', 'j', 'j', 'c', 'g', 'q', '5375', '2819', '8745', 'v', 'h', 'm', 'l', '8263', 'b', 'n', '5959', 'z', '6667', '3919', 'q', 'a', 'l', '3867', 'd', '4437', '7631', 'j', '1745', '4617', '1907']
[A]:
a, b, c, d, g, h, j, l, m, n, q, v, z