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]: ['n', '7337', '6887', '2203', '4663', '2837', '6451', '959', '8027', 'p', 'v', 'q', 'g', '8059', '6151', 'v', '7097', '6583', '7637', '2367', 'w', '9603', '5365', '3773', '1707', 'k', 'x', 's', 'c', 'u', '3641', '6137', '1207', 'k', '5531', '4543']
[EX A]: c, g, k, n, p, q, s, u, v, w, x

[EX Q]: ['r', '9489', 'e', 'n', '6323', 'd', '3163', '265', '8587', '7891']
[EX A]: d, e, n, r

[EX Q]: ['d', 'v', '8853', 'k', '8235', '9353', '4519', '2679', 'f', 'l', 'v', '5247', 'z', 'j', '9687', 't', '8355', 'j', '3891', '4097', '3273', '1721', '8873', '5693', 's', 'j', '6279', '7813', 'm', '7901', 'j', 'b', '8679', 'k', '1535', '4703', '2783', '4615', '1909']
[EX A]:
b, d, f, j, k, l, m, s, t, v, z