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:
['x', 'u', 'm', '8089', '9985', 'e', '2927', 'n', '7085', 'q', 'v', 'f', 'p', '5079', '3339', '7871', 'h', '7389', '733', 'e', '3387', 'b', 'x', 'z', '2039', 'u', '59', '5031', '8115', '5447', '3045', 'x', '6591', '9561', '4315']
answer:
b, e, f, h, m, n, p, q, u, v, x, z


question:
['2381', 'y', '6631', '5839', 'r', 'm', 'z', 'b', '4663', '595', '7771', '5305', '5087', '3317', '3125', '9551', '4343', '5121', 'm', 'i', '131', '8401', '5379', '1775', 'u', '1125', '9793', '4123', 'h', '1613']
answer:
b, h, i, m, r, u, y, z


question:
['1387', 's', 'j', '3257', '6383', '1429', 'i', 'y', '509', '6271', '8591', '2889', '4105', 'd', 'i', 't', 'y', '769', '213', 'd', 'x', 'v', 'u', '3931', '5225', '8909', '1041', 'u', 'c', '2545', '6465', '6267', '9129', '943', '7613', '7807', '7519', 'x', '9629']
answer:

c, d, i, j, s, t, u, v, x, y