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]: ['p', '4329', '2437', '6279', 'u', '459', 'f', 'c', 'i', 'w', 'n', 't', '429', 'n', '73', '4995', 'p', 'z', '8459', '6133', 'y', 'r', '4057', 'a', '2717', '7803', 'r', 'm', '2879', '6989', '7223', 'v', '7929']
[A]: a, c, f, i, m, n, p, r, t, u, v, w, y, z


[Q]: ['6175', '9441', '7127', '5979', 's', '1367', 'e', 'm', '7083', '1787', '8375', '2851', '3475', 'r', '697', 'g', 'z', 'm', '4207', 'c', '7971', 'z', '9339', 'd', 's', '3507', '9003', 'i', 'y', 'w', 'j', 'i']
[A]: c, d, e, g, i, j, m, r, s, w, y, z


[Q]: ['885', 'b', '4077', '2721', '9985', '1623', '7165', 'k', 'm', '8979', 'u', '1891', 'w', '6849', '3425', '6533', 'n', 'p', 'x', '2873', '8603', '1871', '9329']
[A]:
b, k, m, n, p, u, w, x