TASK 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.
PROBLEM: ['3035', 'f', 'k', 'e', '3023', 'p', '9667', '5277', '4757', '8433', 'g', '1399', '7721', 'n', 'p', '7469', '7581', '5679', 'g', 'q']

SOLUTION: e, f, g, k, n, p, q

PROBLEM: ['8821', '9833', 'l']

SOLUTION: l

PROBLEM: ['e', '8325', '7529', 'f', 'h']

SOLUTION:
e, f, h