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.
--------
Question: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']

Answer: j, l, n, q, r, s, y

Question: ['j', 'y', '9907', 'a', '5715', 'l', '9817', '1949', '2697', '2255', '9571', '8957', '9329', '6055', 'z', 'q', '1185', '4593']

Answer: a, j, l, q, y, z

Question: ['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']

Answer:
a, e, f, i, k, l, m, n, o, p, q, s, v