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]: ['1367', 'h', '4153', '1587', 'h', 'b', 'n', 'u', 'n']
[EX A]: b, h, n, u

[EX Q]: ['1657', 'u', '1849', '425', 'v', '6435', 'j', '2985', '921', '9553', '2621', 'i', '7103', 'd', '8563', 'l', 'b', '6727', '4235', 'n', '8021', 'd', 'z', '437', 'm', '5695', 't', '3421', 'e', 'a', '2941', '791', '1417', '9247', 'h']
[EX A]: a, b, d, e, h, i, j, l, m, n, t, u, v, z

[EX Q]: ['9739', '289', '2939', 'd', '7543', 'a', 'x', 'f', 'm', 'y', 'p', '5021', '371', '2481', '8395', '8187', 'q']
[EX A]:
a, d, f, m, p, q, x, y