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.

Example Input: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']
Example Output: b, v, y

Example Input: ['8451', 'x', '9965', '9303', 'm', 'f', '4205', 'y', 'n', '8521', '9995', 'z', 's', '3519', 'k', 'e', 'o', 'k', '9611', 'q', 'l', 'p', '3339', '4023', 'n', 'd', '8903', 'a', 'k', 'u', '4009', 'e', 'm', '989', '4495']
Example Output: a, d, e, f, k, l, m, n, o, p, q, s, u, x, y, z

Example Input: ['7997', '113', '2369', '1351', '2639', 'n', 'p', 'i', 'p', 's', '241', 'm', '5229', 'l', '2193', '8001', '2589', 'o', 'k', 'l', 'a', 'a', 'v', 'f', '389', '8047', 'q', 'e', 'v', '1925']
Example Output:
a, e, f, i, k, l, m, n, o, p, q, s, v