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]: ['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']
[EX A]: r, t, x

[EX Q]: ['7133', 'r', '667', '1979', '7647', 's', 'r', '1387', 'e', 'u', '6737', '1955', '5731', '9865', 'q', 'o', '4307']
[EX A]:
e, o, q, r, s, u