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.

['6643', '6757', 'h', '1033', 's', 'c', '2003', 'p', '5483', 'f']
c, f, h, p, s

['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, c, e, h, l, q, t, v, w, x

['7241', '1963', 'w', 'c', 'w', '9315', 'o', 'z', '8173', '9837', 'o', 'b', '3677', 'z', 'h', '3605', 'q', '1123', '6129', '4209', '3807', '6505', 'l', '5537', '5021', '7327', 'c', 'n', 't']

b, c, h, l, n, o, q, t, w, z