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

A: a, j, l, q, y, z
****
Q: ['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']

A: a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z
****
Q: ['p', 'o', '4487', 'k', '2179', '7527', '4323', 'o', '2207', '5277', 'q', 'w', '8361', '4779', '7303', 'f', '673', '9045', '3599', 'c', 'l']

A:
c, f, k, l, o, p, q, w
****