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: ['2247', 'w', 'h', '4675', '6153', 'f', '6029', 'o', 'd', 'j', 'z', 'y', 'i', '6899', '3917', 'u', '6447', '6405', 'a', '1705', '8585', 'v', 'f', 'r']

SOLUTION: a, d, f, h, i, j, o, r, u, v, w, y, z

PROBLEM: ['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']

SOLUTION: a, g, h, k, m, p, q, r, v

PROBLEM: ['4197', '9439', 'h', '1453', '1699', '6313', 'd', '9995', 'g', 'c', 'q', '7429', '5873', '6563', '6583', '8467', 'h', '9293', 'j', '8663', '1019', 'h', 'd', 'y', '9965', '6429', '8277', '1123', '957', '9049', '5843', 'y', '7485', 's', 'y', '7459', '1389', 'e', 'v']

SOLUTION:
c, d, e, g, h, j, q, s, v, y