Instructions: 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.
Input: ['8617', '7051', '1045', '9507', '765', '4057', 'o', '6191', 'j', 'a', 'f', '7515', 'l', 'n', 'f', 'b', 'w', '2109', 'y', 'k', '6035', '5011', '4281', 'm', 'g', 'y', '8287', '9269', 's', 'v', 't', '5865', '3765', '1345', 'd', 'b']
Output:
a, b, d, f, g, j, k, l, m, n, o, s, t, v, w, y