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]: ['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']
[EX A]: c, d, k

[EX Q]: ['1487', '8003', 'd', '7237', 'l', 'y', '2749', 'e', '9685', '2825', 'z', '7743', 'r', '9617', 'w', '4323', '2173', '8419', '2831', '8923', 'l', '2985', '303', 'y', '9409', 'i', 'h', 'e']
[EX A]: d, e, h, i, l, r, w, y, z

[EX Q]: ['j', 'c', '4131', '3249', '5607', 'p', '3213', '1187', '8137', 'e', '5263', '9657', '2647', '3993', '7249', 'j', '199', '7873', '175', '1893', 'l', '2695', '1809', 'd', 'x', 'b', '5947', '6497']
[EX A]:
b, c, d, e, j, l, p, x