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.

['1429', '7273']
-1

['b', 'd', '8153', 'u', '3695', '5317']
b, d, u

['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

j, m, v, w, x