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: ['d', '771', '4193', 'e', '1537', 'a', 'q']

A: a, d, e, q
****
Q: ['v', '5433', 'v', '6749', '7491', 'i', 'm', 'e', '5815', '8423', '833', '7359', 'm', 'i', 'f', 'u', 'p', 'j', 't', '3171', '6165', 'q', 'a', '9475', 'm', 'q', '5995', '8443']

A: a, e, f, i, j, m, p, q, t, u, v
****
Q: ['a', '5927', '3125', '6041', 'c', 'e', '6017', '7677', 'y', 'w', '7093', '6787', '5947', '5431', '3849', '6913', '5487', 'v', 'm', 't']

A:
a, c, e, m, t, v, w, y
****