Detailed Instructions: 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.
Q: ['5747', 'd', 'r', 'h', '3953', '3773', '1383', '2471', 'k', '7713', '5769', 'k', 'j', '4215', 'c', 'p', 'k', '8339', '925', 's', 'v', '6873']
A:
c, d, h, j, k, p, r, s, v