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.

Example Input: ['k', 'n']
Example Output: k, n

Example Input: ['1653', '3177', 'b', '2785', '2515', 'd', '5513', '5599', '2947', 'v', '2771', '5697', '2913', '4161', '5939', '2655', '6787', '9851', 'q', '3199', 'x', '1305', '9423', '9117', '4821', 'j', '7963', 'i', 's', '469', 'r', 'w']
Example Output: b, d, i, j, q, r, s, v, w, x

Example Input: ['1535', 'z', 'k', '3913', '4425', '7499', 'n', '8927', '7797', '4497', '1537', '1931', 'd', '2645', 'm', 'o', '6767']
Example Output:
d, k, m, n, o, z