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: ['l', 'g', 'd', 'p', '8163', '6643', 'o', 'p', 'm']

A: d, g, l, m, o, p
****
Q: ['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']

A: b, l, o, q, u, v, w
****
Q: ['2307', 'c', '7071', 'd', '1387', 'g', 'q', 'y', '7009', '5407', 'x', '5019', 's', 'l', '97', '4223', 'f', '7983', '1877']

A:
c, d, f, g, l, q, s, x, y
****