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:
['4945', 'i', 'h', 's', '8925', 'i', '3995', 'f', '813', '1823', '3475', 'q', '2463', '9487', 'c', 'c', 'n', 'y', 's', '6269', 'a', 'u', 'd', 'd', '9291', '3187', '545', '7929', 'd', '1007', '7579', '8421', '4033', 'v', 'c', 'e', 'n', 'j']
answer:
a, c, d, e, f, h, i, j, n, q, s, u, v, y


question:
['g', 'x', 'l', 'e', 'd', '1345', '1763', 'm', 'c', '2057', 's', 'a', '4127', 'y', 'h', '8581', 'o', '9203', '4761', 'd', 'u', 'n']
answer:
a, c, d, e, g, h, l, m, n, o, s, u, x, y


question:
['i', 'j', 'd', 'e', '8825', '2201', 'w', 's', '8265', 'p', '6433', 'a', 'u', '1067', 'w', 'l', '6417', '1019', '5333', 'z', '8285', '2129', '3569', 's', 'k', 's', '4179', 'v', '5231', '2239']
answer:

a, d, e, i, j, k, l, p, s, u, v, w, z