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]: ['p', 'k', 'i', '753', 'u', 'm', '3817', '1597', 'l', 'm', 'a', 'i', 'b', 's', 'c', '2561', 'x', '5363', '1173', '8657', '2033', 'b', 'p', '3093', 'k', '6535', '307', '9925', 'b', 'q', 'q']
[EX A]: a, b, c, i, k, l, m, p, q, s, u, x

[EX Q]: ['565', 'i', '615', '3047', 'm', '195', '7547', '3003', '9213', '9063', 'c', '5099', 'v', '5003', '9053']
[EX A]: c, i, m, v

[EX Q]: ['c', '4049', 'w', '9777', '5531', 'm', 'k', 'g', '4791', 's', 'l', 'm', 'r', 'r', 's', '5709', '4249', 'o', 'e']
[EX A]:
c, e, g, k, l, m, o, r, s, w