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]: ['5039', '2227', 't', 'o', '3313', 'm', 'v', '637', '6773', 'v', 'c', 'l', 'y', 'u', '3823', '9669', 'k', 'h', '3589', 'b', 'i', '3833', 's', 'm', '8201', 'u', '3143', 'k', '4111', '9769', '425', '4339', '209', 'c', 'c', '669', '8201', 'u', '7443', '2387', '6919', 'b', 'b', '2873']
[A]: b, c, h, i, k, l, m, o, s, t, u, v, y


[Q]: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']
[A]: b, e, l, m


[Q]: ['7055', '2573', '1713', 'x', 'm']
[A]:
m, x