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]: ['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']
[A]: b, i, k, u, z


[Q]: ['t', 'r', '2959', '2517', 'a', '9959', '729', '511', 'y', 'r', '465', 'c', '687', 'm', 'b', 'm', '3449', '9713', 'g', '8275', '8823', 'a', 'z', 'w', '2185', '6283', '8457', '8137', '7163', '8329']
[A]: a, b, c, g, m, r, t, w, y, z


[Q]: ['i', 'a', '7297', '2521', 'i', '9247', 'c', 'c', '5817', '3691', '4995', '4811', 's', '6209', '9431', '7351', '8539', '3185', 'c', '2449', 'j', '7655', 'f', 's']
[A]:
a, c, f, i, j, s