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: ['2741', '2541', '8943', 'l', '4047', '2211', 'p', 'e', 't', '7645', '9771', 'f', '5063', '2303', '6097', '5089', 'd', 'e', '1409', '3125', '2171', 'g', '1247', '4045', 'v', 'h', 'u', '2587', '5207', '5553', 'g', 'd', '6891', 'e', '2471', '2435']

SOLUTION: d, e, f, g, h, l, p, t, u, v

PROBLEM: ['4993', '6641', '3127', '9409', '8453', '5909', '6109', 'y', 'f', '6859', 'c', '3863', 't', '1221', '3689', 'w', 'h', '7947', 't', '5979', 'l', 'i', '1321', '3149', 'l', 'v', '3825', 'z', '9297', 'f', 'e', '7205', 'a', 'a', '2645', '391', '4965', 'w', 'h', '7715', '9409', '3603', '4147']

SOLUTION: a, c, e, f, h, i, l, t, v, w, y, z

PROBLEM: ['565', '8507', 'k', '8649', 'v', 'x', '8021', 't', '3997', 'o', 'v', '2639', 'e', '5349', 'd', '9451', 'r', '3831', 'h', 'v', 'e', 'd', 'k', '4665', '5325', '2873']

SOLUTION:
d, e, h, k, o, r, t, v, x