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: ['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

A: b, e, n, t, y
****
Q: ['d', '1989', '6365', 'y', 'm', '1245', '7539', 'm', '3787', '6987', 'e', 'e', 'y', '9577', 'b', '5', '8179', 'x', '2853', '6337', 'w', 'f', 'b', 'q', '563', '6077', '1133', 'x', '6045']

A: b, d, e, f, m, q, w, x, y
****
Q: ['4203', 'p', 'a', '8175', 's', '6059', '6677', '8177', '7169', '2083', '7709', 'c', 'v', 'g', '5485']

A:
a, c, g, p, s, v
****