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', 'h', 'q', '7185', 'f', 'l', 'r', '3605', 'x', 'i', 'v', '8789', 'u', 'x', 'x', '8315', 'x', 't', 'h', 'o', '4943', '5827', '7677']

A: f, h, i, l, o, q, r, t, u, v, x
****
Q: ['9483', '501', 'j', 'k', '3103']

A: j, k
****
Q: ['f', '7953', 'k', '4253', '5029', '2875', '6743', 'c', 'a', 'x', 'u', '9233', 'x', '2397', '9583', '4779']

A:
a, c, f, k, u, x
****