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: ['p', '2923', 'e', 'k', '5433', '605', '5079', 'k', 'p', 'x', '4845', '4099', '6795']
Example Output: e, k, p, x

Example Input: ['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']
Example Output: f

Example Input: ['433', 'b', 'c', '8495', '2423', 'c', 'y', '9437', '1371', 'h', '5739', '3639', 'r', 'd', '7929', '1365', 'x', '1947', 'j', '4105', 'q', 'f', 'z', 's', '7097', '2949', '9357', 'j', 'h', '8733', 't', '9215', 'i', '9327', '3455', '9827', 'o', '7897', 'd', '5179']
Example Output:
b, c, d, f, h, i, j, o, q, r, s, t, x, y, z