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: ['p', 'f', 'h', '1977', '6221', 'i', 'a', 'l', '5225', '8059', 'c', 'w']

Output: a, c, f, h, i, l, p, w


Input: Consider Input: ['1447', 'q', '9529', '2971', 's', '7351', '6753', '3493', 'v', 'c', 'x', '3097', '9145', 'b', 'e', 'b', '2967', '6933', 'e', 's', 'v', 'f', 'z', 'r']

Output: b, c, e, f, q, r, s, v, x, z


Input: Consider Input: ['5929', '5439', 'r', '2431', 'r', '6469', 'z', '9235']


Output: r, z