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: ['7187', '7081', 'j', 'i', '3725', '6333', 'h', 'f', '6639', 'r', 'n', '3559', '2785']

A: f, h, i, j, n, r
****
Q: ['5433', '4011', '2113', '2299', 'e', '9829', 'd', 'q', 'e', '3921', 'a', 'q', '8953', 'q', 'g', 'w', 'z', 'u', '4425', 'b', 'q', '5315', 'b', 'u', 'h', 'y', '9733', 'b', 'c', '1225', 'a']

A: a, b, c, d, e, g, h, q, u, w, y, z
****
Q: ['g', '9567', 'b', 'f', '785', 'x', 'r', 'u', 'q', 'u', '4685', 'n', 'g', '1139', 'b', 'l', '7355', '6003', 'v', '7873', '727', 'p', 't', 'n', '5907']

A:
b, f, g, l, n, p, q, r, t, u, v, x
****