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:
['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']
answer:
c, d, e, g, i, j, l, p, q, t, u


question:
['u', '8229', '2731', '6595', '4675', 'n', 'a', '7361', '7401', '7273', 'b', '279', '5539', '7919', 'j', 'x', '9521', '8837', '7391', 'h', 'x', 'h', '7283', 't', '3769', '2317', '9131', 'h', 'y', 'c', '1625', 'm', 'e', 'a', '8437', '7543', 'p', '2451', 'k', 'r']
answer:
a, b, c, e, h, j, k, m, n, p, r, t, u, x, y


question:
['l', '7441', '7665', 'w', '8557', 'y', '3227', 'x', 'o', 'h', 'u', '8015', '2305', 'o', '2059', 'g', 'o', '3337', 'u', '4151', 't', 'z', '1575', 'f', '2487', '1387', '9343', '9249', '3887', 'n', '6863', 'f', '8293', 'd', '2991', '6937', '9113', '9037']
answer:

d, f, g, h, l, n, o, t, u, w, x, y, z