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]: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']
[A]: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y


[Q]: ['w', '1367', '5389', '9515']
[A]: w


[Q]: ['2911', '2421', 'g', '4781', 'k', 'v', 'n', 'k', '4139', '9469', '5943', '3231', 'y', 'e', 'a', 'n', '3421']
[A]:
a, e, g, k, n, v, y