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: ['7591', '1403']

Answer: -1


Question: ['e', '2239', 'l', '8309', 'i', '2613', 'i', '611', '6481', 'j', 'v', '1867', '415', '269', '8053', '3369', 'q', 't', '2303', '7729', '1059', '6135', '3299', 'd', '6855', '207', '6227', '7859']

Answer: d, e, i, j, l, q, t, v


Question: ['5545', 'c', 'n', 'k', '2883']

Answer:
c, k, n