Definition: 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.
Input: ['j', 'r', '7253', '1999', '8739', '4567', 'x', 'a', 'j', '4385', '5165', 'k', '3167', '771', '7537', 'r', '5589', 'w', '5199', '6863', '8185', '9847', '4495', '6721', 'v', '387', '3435', 'n', 't', 'v']
Output:
a, j, k, n, r, t, v, w, x