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: ['8879', 'x', '1383', '4925', '2867', 'j', 't', 'e', 'w', 'p', 't', 'w', 'l', '7447', '1877', '7747', 'k', 'b', 'x', '8565', 'q', '8575', '5711', '2949', '5637', '2197', '4905']

A: b, e, j, k, l, p, q, t, w, x
****
Q: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

A: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y
****
Q: ['4545', '1397', '1397', 'f', 'm', '1927', 'n', 'd', 'd', 'm', 'u', '5503', '2269', 'c', '3589', '259', '1477', 'w', 'f', '6399', '8615', '2013']

A:
c, d, f, m, n, u, w
****