instruction:
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.
question:
['333', 'b', '261', 'k', 'p', '7861']
answer:
b, k, p


question:
['i', 'h', '8299', 'e', 'c', '5543', '5241', 'f', '3985', 'f', 'z', '1245', 'e', 't', 'g', '5199', '9217', 'q', 'j', 'p', '767', 'z', '1803', 'k', '7303', '3187', '2507', '6471', '3337', '6037', '9291', 'a', 'l']
answer:
a, c, e, f, g, h, i, j, k, l, p, q, t, z


question:
['s', '7785', '1185', '149', 'q']
answer:

q, s