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: ['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

A: c, e, f, m, o
****
Q: ['g', 's', 'v', '5813', '3461', 'a', '7899', 'd', '1753', 's', 'k', '6911', '4049', 'k', 'u', 'w', 'e', '9035', 'e', 'b', 'v', 'z', 'c', '139', 'd', 'h', '4919', '5301', '1203', '1695', 'r', '2427', '6663']

A:
a, b, c, d, e, g, h, k, r, s, u, v, w, z
****