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', '771', '4193', 'e', '1537', 'a', 'q']

A: a, d, e, q
****
Q: ['c', '9125', '6049', '5201', 'v', '9311', 'q', '3305', 'l', 'q', '3387', '3647', 'x', '471', 'a', '5631', 't', '9679', '5423', '2569', 'w', 't', '6397', 'e', 'h', 'c', 'v', 'v']

A: a, c, e, h, l, q, t, v, w, x
****
Q: ['k', '489', '2253', '3837', 'm', '2953', '2975', '9335', 'r', '8239', 'g', 'o', '691', '4881', 'e', 'k', '4595', 'y', '6205', 'o', '1517', 'd', 'w', '7999', '5727', '3517', 'c', 'k', '5781']

A:
c, d, e, g, k, m, o, r, w, y
****