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:
['6697', 'j', '1571', '4989', 'o', '1143', 'i', '2969', '2541', '4899', 'i', '4751', 'n', 'b', '801', '4357', '3855', '49', 'm', '211', '7281', '121', '5231', '8313', '8967', '8043', '7699', 'r', '4315', '8637', '3339', '4437']
answer:
b, i, j, m, n, o, r


question:
['n', 'h', 'h', 'e', 'p', '1265', '4853', '9433', '1227', '1619', '6381', 'o', '8285', 'k', 'u', '7471', 'm', '6887', '6579', '5813', '5563', '8535', 'n', '3743', 'h', 't', '4497', '2791', 'e', 'v', '6769', '7969', 'x', 't', 'x', 'q']
answer:
e, h, k, m, n, o, p, q, t, u, v, x


question:
['j', 'f', 'b', 'p', '5351', 'l', '5195', 'j', '4537', '5979', 'n', '3089', '5391', '7129', 't', '9029', '9215', '5413', 'a', '625', 'a', 'p', '7313', '1219', 'y', 'o', 'v', '2203', 'o', '5083', 'e', 'w', '263', 'j']
answer:

a, b, e, f, j, l, n, o, p, t, v, w, y