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', 'u', 'y', 'y', 'b', 'x', 'q', '3713', '2679']
[A]: b, q, t, u, x, y


[Q]: ['l', '1213', 'm', 'k', '7825', '3501', '2397', '2313', 'v', '4119', 'h', 't', '6137', 'l', '9851', 'q', '9661', 'b', 'z', '1437', '1759', 'l', '611', '5085', '4443', 'n', 'u', 'b', '2511', '6023', '7157', 'n', '9921', 'o', 'a', 'o', 'w', 't', 'o', '1607', '6751', 'n', 'b']
[A]: a, b, h, k, l, m, n, o, q, t, u, v, w, z


[Q]: ['2343', '7639', 't', '1959', '8747', '3089', 't', '3319', 'c', 'e', 'a', 'c', '3199', '5603', '5853']
[A]:
a, c, e, t