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: ['t', '5809', 'z', 's', '8917', 'z', 't', 'j', 'i']

i, j, s, t, z