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: ['w', '9437', 's', '9819', 'q', 'q', '4443', 'p', '377', '6777', 's', 'x', 'a', 'o', '9205', '9289', '7103', 'k', 'l', '9453', '9043', 'k', 'r', 'g']

A: a, g, k, l, o, p, q, r, s, w, x
****
Q: ['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']

A: f, r, w, y
****
Q: ['139', '8321', '9201', '6535', '7689', '4793', 'g', 'p', 'r', 'c', 'c', '4549', 'j', '1717', '4821', 'l', 'k', 'l', '9531', '973', 'z', '409', '921', '2001', 'z', '9187', 't', '6537', '3313', '1151', 'e', '1253', '1795', '9837', '6473', '3251', '1705', '3265', 'q', '5215', '9465', 'b', '7323', '2889', '1755']

A:
b, c, e, g, j, k, l, p, q, r, t, z
****