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: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

A: f, k, n, p, q
****
Q: ['x', 'j', '9747', 'i', '2015', '3505', 'q', 'n', 'h', '3011', 'u', '8043', 'j', 'f', 'd', 'a', 'p', '5817', 'l', 'q', '2275', 'n', '7085', '5373', 'l', 'g', 'b', '8043', '3085']

A: a, b, d, f, g, h, i, j, l, n, p, q, u, x
****
Q: ['h', '9509', '5063', 'u', '2029', '3209', '4151', 'y', 's', '2721', 'r', '9053', '6413', '5949', 'v', '687', '2443', 'd', '8507', '8921', 'u', '6845', '3547', '4503', 'e', 'g', '6387', 'a', 'g', '4995', 'v', '7763', 'm', 'd', 'b', 'i', 'h', '2769', 'a', '9799', '2709', '2067', 'q']

A:
a, b, d, e, g, h, i, m, q, r, s, u, v, y
****