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: ['q', 'g', 's', 'g', 'z', '987', '777']

A: g, q, s, z
****
Q: ['w', '1081', 'n', '2073', 't', '6351', '5591', 'a', '113', 'w', 'q']

A: a, n, q, t, w
****
Q: ['4589', 'm', '2681', 'h', 's', 'u', 'i', 'v', 'v', '8647', 'g', '5475', 'z', '7481', 'y', '103', '5939', 'u', '4619', 'r', 'h', '2667', 'l', 'w', '259', '7541', '8083', 'i', '2919', 'q', '9681', '2491', '6741', '3867', '9141', '9621']

A:
g, h, i, l, m, q, r, s, u, v, w, y, z
****