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: ['1655', '1321', '9109', 'z', '7321', 'p', 'b', '5323', 'j', '5089', '2287', 'n', 'h', '9359', '8659', 'f', '3017', '3287', '3757', 'q', 't', '9931', 'p', 'f', '8667', '9223', 'g', '921', '7235', 'k', '8339']
Output:
b, f, g, h, j, k, n, p, q, t, z