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: ['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']

Answer: e, l, n, p, q, r


Question: ['u', '4021', 'u', 'd', 'j', 'p', 'i', 'z', '3223', 'f', 's', 'l', 'p', 'd', '5031', '1059', '7875', '2097', 'q', 'i', '8813', '2017', 'h', 'l', 'y', '57', '1561', 'f', 'j', 'z', '1901', 'u', 'j', 'x', '6561', '9239', '3333', '8793', '4915', '5821', 'h', 'f', '765', 'x']

Answer: d, f, h, i, j, l, p, q, s, u, x, y, z


Question: ['c', '1177', '9619', 'w', '649', 'n', '6601', 'a', 'q', '6149', '7817', '657', 'u', 'c', '5939', 'n', 'a', 'g', 'r', 's', 'i', 'm', 'o', '1023', '5385', 'c', '7385', '4667', '2471', '2889', '6327', '9049', 'p', '3177', '8383']

Answer:
a, c, g, i, m, n, o, p, q, r, s, u, w