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: ['i', '1191', '5581', '2527', 'g', '9795', '519', 'u', '8389', '9793', 'k', '5733', '7125', '7835', 'j', '855', 'd', 'd', '6555', '3211', 'l', 'o', 'b', '523', 'x', 'j', '1707', '4161', '7171', 'h', 'h', 'm', 'h', '2443', 'e', '649', '951', 'n', 'h']

SOLUTION: b, d, e, g, h, i, j, k, l, m, n, o, u, x

PROBLEM: ['u', '1343', 'd', 'c', '9567', 'e', 'd', 'y', 's', '4199', '3217', '2937', '9345', 'd', 'l', '9875', '5987', 'p', '2585', '5843', '9643', '2423', 'e', 'l', 's', '3503', 'b', 'w', '9685', 'p', '6055', 'k', 'e', 'e', 't', '865', '6071', 'j', '3439', 't']

SOLUTION: b, c, d, e, j, k, l, p, s, t, u, w, y

PROBLEM: ['5355', '8525', 'b', 'g', '899', '7353', '7305', '5361', '1931', '9697', '9805', 'g', '2549', '9121', '7635', '4065', '6649', '4503', 'o', '77', 'y', '7133', '1559', '5173', '5889', '4213', 'h', '3379', 'c', 't', 'u', '4285', '9051', '9853', 'g', 'e', '9567', '7067', 'd', 'z']

SOLUTION:
b, c, d, e, g, h, o, t, u, y, z