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]: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']
[EX A]: f, g, i, k, l, r, z

[EX 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']
[EX A]: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y

[EX Q]: ['9789', 'r', '7097', 'l', '295', 'y', 'k', '5731', 'b', '8397', '3863', 'g', '1835', '4605', '8041', 'q', '6917', 't']
[EX A]:
b, g, k, l, q, r, t, y