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:
['8357', 'x', 'w', '287', 'z', '2733', '1757', 'w', 'g', '1393', '7201', '4931', 'k', '5185', 'x', '6313', '2255', 'z', 'v', '3593', '6191', '4423', 'm', 'k', '3209', '3559', 'c', 'n', 'm', '5461', '2997', '235', '4045', '6597', 'v', 'e', 'p', 'c', 'k', 'd', '5529', '6241', 'u', 'f', '8067']
answer:
c, d, e, f, g, k, m, n, p, u, v, w, x, z


question:
['1223', 'h', 'a', 'o', 'v', '2535', 'g', '6267', 'w', '9625', '7961', '9577', '7611', '5655', 'p', 'j', 's', '2141', '4101', 'l', '4367', '9383', 'n', '5965', '9097', '7571', 'p', 'u', 'x']
answer:
a, g, h, j, l, n, o, p, s, u, v, w, x


question:
['u', '5889', '6003', '631', '1169', '869', '7279', '3247', '4655', '5641', '2163', 'k', 't', 'e', '5133', 's', '3131', '1911', 'm', 'x', 'h', '2923', '5005', 'o', '921', '9085', '5733', 's', '5017', 'o']
answer:

e, h, k, m, o, s, t, u, x