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]: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']
[EX A]: j, m, v, w, x

[EX Q]: ['2915', '6033', '5541', '4685', '1263', '6701', 's', '7269', 'g', '8033', '8171', '6917', 'l', '2913', '447', 'g', 'a', 'z', 'o', '7563', '5385', '5259', '5067', '4869', '2653', '6925', '7001', '8553', 'x', '1243', '9131', '5037']
[EX A]: a, g, l, o, s, x, z

[EX Q]: ['l', '4621', 'i', 'k', 'b', 'h', '9317', '7519', 'e', '451', '2007', 'e', 'k', '8759', '3809', '1731', '555', 'b', '6409', '9607', 'o', '8953', 'm', 'a', 'p', '3595', '2567', 'v', 'a', '2197', 'e', '1647', '4723', 'm', 'e', '9797', 'x']
[EX A]:
a, b, e, h, i, k, l, m, o, p, v, x