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: ['9483', '501', 'j', 'k', '3103']

A: j, k
****
Q: ['d', 'o', '7643', '9065']

A: d, o
****
Q: ['5471', '3723', 't', '8429', 'm', 'w', 'c', 'q', '7259', 't', 'p', '9305', 'l', '5799', 'k', '5947', '3427', 'l', 'd', 'a', '8301', 'a', '6083', 'o', 'z', '1343', '7681', 'l', 'p', 'x', 'b', 'k', '7835']

A:
a, b, c, d, k, l, m, o, p, q, t, w, x, z
****