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]: ['z', '8763', '6399', '45', '6731', 'v', '441', '4763', 'u', '8741', 'r', '9143', 'd', 'p', '2241', 'y', '6523', 'y', 'w', '6771', 't', 'r', '9239', '295', 'z', '461', 'b', '9217', '2597', '1249', 'r', 'i']
[EX A]: b, d, i, p, r, t, u, v, w, y, z

[EX Q]: ['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']
[EX A]: b, i, k, u, z

[EX Q]: ['e', 'e', '8329', 'i', 'u', '1141', 't', 'b', '3831', 'k', '8365', '6569']
[EX A]:
b, e, i, k, t, u