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: ['491', '229', 'g', '6677', '4793', 'h', 'x', 'a', '2333', 'u', 'l', '785', 'p', '7331', '653', '5193', '5415', '8417', 'v']

A: a, g, h, l, p, u, v, x
****
Q: ['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']

A: b, d, e, f, g, l, m, p, r, s, t, u, v, w, z
****
Q: ['2855', '2867', 'o', '4867', 'f', 'r', 'h', 's', '5851', 'r', '13', 'c', 'a', 'd', '2567', '3093', '5623', '7573', 's', 'w', '2625', 't', '5533', 'y', '7675', '2195', 'i', '65', 'v', '2587', '6319', '3531', '807', 'o', 'q', '6045', 'm', '6779', 'k', '8733']

A:
a, c, d, f, h, i, k, m, o, q, r, s, t, v, w, y
****