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]: ['y', 'g', '107', '4899', '6357', '9777', 'k', '1865', '7029', 'q', 'x', '7051', 's', '6125', '4285', '2731', 'z', 'a', '737', '6137']
[EX A]: a, g, k, q, s, x, y, z

[EX Q]: ['9271', '6393', '6005', 'x', '2301', '3999', 'p', 'z', 'j', '1033', '7555', 'r', 'r', 'y', '8917', '5939', '4031', 'e', '8095', 'g', '6095', 'a', '4133', '6471', '2129', '8021', '1093', 't', '8805', '545', 'k', '3249', 'l', '1561', '9909', 's', '1963', 'o']
[EX A]: a, e, g, j, k, l, o, p, r, s, t, x, y, z

[EX Q]: ['w', 'b', 'x', 'z', 'h', '4195', 'd', 'm', 'j', '4047', 'c', '9015', '2371', 'w', '4371', '1283', 'r', '8135', 'y', '9591', 't', 'g', '5249']
[EX A]:
b, c, d, g, h, j, m, r, t, w, x, y, z