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]: ['i', 'y', '8339', 'd', 'b', '7471', '6577', '9037', '4503', '6287', '1439', '8863', '9201', '2661', 'x', 'l', 'v', 'w', 'a', 'f', '8885', '519', '7631', 'g', '7203', '8605', '2429', '9165']
[EX A]: a, b, d, f, g, i, l, v, w, x, y

[EX Q]: ['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']
[EX A]: c, e, u

[EX Q]: ['l', '4265', 'p', '6769', '2955', 'm', 'b', '1315', 't', '3851', '9517', 'w', 'x', '7325', 'i', '8085', 'l', '7997', '3965', 'x', '4217', '913']
[EX A]:
b, i, l, m, p, t, w, x