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.

[EX Q]: ['r', 't', '3539', 'z', 't', '6055', 'r', '5787', '8469', 'p', 'h', '9729', 'z', '1637', '5873', 'c', '3597', '4411', 's', 'k', 'q', '6471', '5375', 'e', 'v', 'i', '7425', 'h', '9079', 'd', '1585', '6011', 'x', '5669', '5219', '4951', '4765', '8285', '2811', 'c', '1805', '6463']
[EX A]: c, d, e, h, i, k, p, q, r, s, t, v, x, z

[EX Q]: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']
[EX A]: c, k, l, m, n, p, w, x

[EX Q]: ['e', '7091', 'd', '4867', 'd', '6689', 'r', 'j', '2213', 'w', '8447', 'h', '1399', 'a', '2691', 'g', 'a']
[EX A]:
a, d, e, g, h, j, r, w