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]: ['6143', 'y', '5505', '9813', 'r', 'v', 'u', '8681', '2387', 'u', 'o', 'm', '9793', 'm']
[EX A]: m, o, r, u, v, y

[EX Q]: ['u', 'k', 'd', '4393', 'u', 'h', 'q', '833', 'k', 'l', '5749', 'r', '7123', '1003', 'z', '531', 'o', 'u', '6601', '6975', '4905', 'n', 'e']
[EX A]: d, e, h, k, l, n, o, q, r, u, z

[EX Q]: ['r', 'w', '9189', '2077', '6419', '5583', '5939', 'n', '835', 'z', '1591', 'v', 'd', 'l', 'e', 'p', '7117']
[EX A]:
d, e, l, n, p, r, v, w, z