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: ['6181', 'w', '4663', '5507', 'a', '6607', '869', '2669', 'r', '3629', 'r', 'l', '6599', '8885', 's', '4315', 'z', 'l', 'r', '1225', '8371', '1545', '7169', '1175', 'k', 'p', 'y', '7263', '5537', '8649', '3317', 'q', 'r', 'u', 'd', '4647', 'u', 'y', 'h', '9753', 'q', '725']

SOLUTION: a, d, h, k, l, p, q, r, s, u, w, y, z

PROBLEM: ['o', '1217', '449', 'n', 'e', 'o', 't', '9043', '1925', '5687', '7197', '7943', 'u', '5053', 'q', 'e', '89', 'l', 'h', '3083', '4295', 'o', 'n', '6309', '743', 'n', 'j', '2105', 's', '6845', 'p', 'p', '1355', '3757', 'v', 'f', '961', '4623', '4633', 'p', '4593', 'p', '7337', 'o', 'u']

SOLUTION: e, f, h, j, l, n, o, p, q, s, t, u, v

PROBLEM: ['1365', 'q', '2283', '6441', '6899', 'e', 'k', 's', '5309', 'h', 's', 'f', 'a', '7467', '5571', '2525', '5169', 'l', '6961', 'e', 'd', 'f', 'l', '6923', '7351']

SOLUTION:
a, d, e, f, h, k, l, q, s