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: ['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']
Example Output: a, c, e, o, r, s, z

Example Input: ['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']
Example Output: a, e, i, n, p, q, r, s, t, u, x

Example Input: ['6635', 'p', '6567', '3907', '4237', 'i', '5575', 'e', '3013', '7223', '2437', '8897', '1385', '3461', '5127', 'r', '81', 'g', '1711']
Example Output:
e, g, i, p, r