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: Consider Input: ['w', '1367', '5389', '9515']

Output: w


Input: Consider Input: ['c', '1693', 'l', 'u', 'x', '3609', 'h', '4159']

Output: c, h, l, u, x


Input: Consider Input: ['m', '3575', '2971', 'r', 'u', '1313', 'e', '1691', 't', 'h', 'b', '7329', 'n', 'c', '9855', '8933', 'h', '4221', 'b', 'u', 'i', 'c', '5453', 'a', 'w', 'b', 'p', '9961', '6539', 'q']


Output: a, b, c, e, h, i, m, n, p, q, r, t, u, w