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', 'c', 'r', '4459', 'o', '1407', 'x', '1515', '331', 'm', '1535', 'p', 'u', 'g', '2513', 'o', '7827', '8149', 'd', 'z', 'q', '5655', 'x', '9997', '2809', 'g', 'h', '6309', 'a', 'j', '9773', '2115', 't', '9113', 'q', 'o', '427', 's', '3815', '5423', 's', 'n', 'i', 'o', '3643']

A: a, c, d, g, h, i, j, m, n, o, p, q, r, s, t, u, x, z
****
Q: ['8975', '7199']

A: -1
****
Q: ['3155', 'a', 'r', 'j', '4027', '2999', 'z', 'o', 'k', '2689', 'r', 'y', 'o', 'm', 'g', '727', 'k', '5327', 'k', 'x', '9697', 'f', '6801', 'a', 't', 'u', '1305', 'r', 'w', 't', 'm', 'x']

A:
a, f, g, j, k, m, o, r, t, u, w, x, y, z
****