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: ['4925', '9943', '7935', '4387', '2449', '5797', 'i', '1517', 'w', 'e', '9525', 'y', 't', 'e', '2793', 'v', '9897', '8709', '7247', 'o', 'f', '5549', 'q']

A: e, f, i, o, q, t, v, w, y
****
Q: ['s', 's', '6581', 'e', '7355', '1315']

A: e, s
****
Q: ['3291', '6645', 'j', 'f', 'e', '2101', '7821', '7713', '2103', '7995']

A:
e, f, j
****