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: ['d', '2359', '6571', 'c', 'n', 'u', '9513', '9321', '1689', 'b', '969', '1823', 'e', 'b', '9147', 's', '1811', 'k', '5443', '8699', '5483', 'v', 'w', 'n', '1215']

A: b, c, d, e, k, n, s, u, v, w
****
Q: ['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

A: b, c, d, f, h, p, s, u
****
Q: ['5473', '3937', '6591', '2237', 'h', '8473', '7573', 'h', '7591', '5087', 'j', '8749', 'w', '1183', 's', 'o', '1479', '9473', 'a', '3523']

A:
a, h, j, o, s, w
****