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: ['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']

A: a, b, e, h, l, q, s, y, z
****
Q: ['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']

A: i, j, o, w
****
Q: ['3667', '6759', 'u', '4149', 'x', '2683', 'd', '3321', 'y', 'w', 'o', '3951', '1575', '8735', 'j']

A:
d, j, o, u, w, x, y
****