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: ['6249', '1235']

Answer: -1


Question: ['z', 'l', '1759', 'k', '8197', 'v', '931', '2587', '7219', '3455', 'e', '8135', 'm', 'n', 'm']

Answer: e, k, l, m, n, v, z


Question: ['1567', 'v', 'p', '6651', '3169', 's', '1821', '7537', '4595', '9043', 'i', '1477', 'p', 'l', 's', 'l']

Answer:
i, l, p, s, v