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', 'i', 'k', 'c', 'f', '3057', '481', '5887', '847', 'c', 'x', 't', 'g', '5805', 'a', 'i', '2885', '403', 'x', 'c', '4815', '2765', 'c', '5181', 'l', 'e', '3843', '1171', 'u', '7867', 'z', 'e', '9349', '5011', 'h', 'x', '3193', 'i', '4595', '8621', '6007', '1879']

Answer: a, c, e, f, g, h, i, k, l, t, u, x, z


Question: ['9113', '3625', 'u', '8189', '3649', '259', '5539', '1583', 'g', '4037', 'y', 'v', '8337', 'd', 'q', 'j', 'c', 'h', 'p', '1601', 'z', 'c', 'n', '1767', '1679', '1805', 'm', '4469', '2487', '6015', '973']

Answer: c, d, g, h, j, m, n, p, q, u, v, y, z


Question: ['t', '6485', '8743', 'o', '8455', 'm', 'a', 'z', 'j', '6601', '1891', 'd', '3739', '2035', '311', '5651', 'v', 'r', 'l', '5201', '9239', 'n', '2795', '2351', 'f', '2891', 'l']

Answer:
a, d, f, j, l, m, n, o, r, t, v, z