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: ['5761', '2289', '577', 't', '125', 'i', 'g', '9693', '747', 'd', '4829', '9587', 'f', 'k', 'w', 'v', '8607']

A: d, f, g, i, k, t, v, w
****
Q: ['5163', 'n', 'j', '67', '3801', 'n', '7113', 'z', '579', '6885', '8921', 'v', '5481', '5507', 'k', '8403', 'c', '837', 'u', '6341', 'd', 'i', '497']

A: c, d, i, j, k, n, u, v, z
****
Q: ['g', 'p', '4217', '1937', 'b', 'a', 'u', 'r', 'u', '4603', 'm', '1005', 'o', '119', '9023', 'w', 'x', '4999', 'z']

A:
a, b, g, m, o, p, r, u, w, x, z
****