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: ['3611', '6825', 'j', 'e', 'r', 'a', '8889', 'y', 'x', 'k', '2651', '4545', '2289', 'r', 'q', '3163', 'a', 'i', 'j', 't', 'b', '2673', '4307', 'q', '5839', 'w', 'g', '6221', 'g', 'h', 'h', '5815', 'n', '3551', '7709', 'z', '2281', '7987', 'w', 'a', '2319', '3337', '3409']

SOLUTION: a, b, e, g, h, i, j, k, n, q, r, t, w, x, y, z

PROBLEM: ['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

SOLUTION: b, e, n, t, y

PROBLEM: ['5891', '6709', 'b', 'o', '4895', 'b', '2457', '2143', '3573', 'q', 'd', '6099', 'c', '5889', 'w', '5053', '527', '6099', '7701', '6509', 'c', '219', '9131', 'e', 'w', '9367', '1009', 'k', 'z', 's']

SOLUTION:
b, c, d, e, k, o, q, s, w, z