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]: ['u', 'd', '4193', '5687', 'p', 'r', '7787', 't']
[EX A]: d, p, r, t, u

[EX Q]: ['5785', 'c', 'f', '7087', 'd', '9225', 'm', 'g', '4639', '7165', '3445', '3813', 'p', 'i', '719', 's', 'g', '6423', '9563', 'w', 'm', '8659', '8809', '4105', '3923', '465', '5637', '5547', 'h', 'v', '9453', '4009']
[EX A]: c, d, f, g, h, i, m, p, s, v, w

[EX Q]: ['i', 'w', '8915', 'x', 'c', 'x', '7527', '6055', '7583', 'e', '2389', '3965', 'z', 'u', 'u', 'k', 's']
[EX A]:
c, e, i, k, s, u, w, x, z