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:
['8301', 'd', 'p', 'l', 'm', '9099', 'o', '8045', 'e', 's', 't', '8853', 'v', '6375', 'q', '2505', 's', '4219', '3587', 'g', '651', '7129']
answer:
d, e, g, l, m, o, p, q, s, t, v


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:
['3001', 'v', 'o', '4817', '4197', '9951', 't', 'u', 'k', 'n', '4779', 'y', '3955', '4843', '2665', 'j', 'i', 'n', 't', 'd', 'z', 'e', '53', 'i', 'l']
answer:

d, e, i, j, k, l, n, o, t, u, v, y, z