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.

[EX Q]: ['o', '1099', 'r', '8995', 'o', '2909']
[EX A]: o, r

[EX Q]: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']
[EX A]: b, v, y

[EX Q]: ['3187', '5111', '81', 'z', '9771', 'd', 'd', 'x', '9047', '1199', '7385', '471', '975', '5645', '2731', 'i', 'w', 'w', '7205', '3975', 'c', 'h', 's', '3013', 'b', '7115', 's', 'j', 'x', '7813', '7951', 'q', 'i', '5559', '2211', 'm', '7827', '675', 'p']
[EX A]:
b, c, d, h, i, j, m, p, q, s, w, x, z