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: ['1627', 'r', '2429', 'b', '4451', 's', 'k', 'm', '269', 'l', '709', 's', 'q', '985', 'x', 'j', 'k', 'k', '6603', 'v', '9497', '477', '5803', 'c', 't', 'f', '3189', '6419', '8561', '5709', 'u', 'z', '5717', '9711', 'w', 'y', 'm', 'v']

SOLUTION: b, c, f, j, k, l, m, q, r, s, t, u, v, w, x, 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: ['r', '5285', 'y', 'j', 'o', '3213', 'r', '8261', '4817', '3669', 'c', 'r', 'v', 'n', '503', '9479', '6697', '6741', '8971', '3147', 'f', '179', '6325', 'e', 'v', 'w', '7311', 'y', '759', 'e', '1087', 'v']

SOLUTION:
c, e, f, j, n, o, r, v, w, y