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: ['7595', '5303', '3985', 'n', 'w', 's', 'r', 'f', '8237', 'q', 'y', 'f', '3121', '2463', '4597', 'q', '6801', 'f', 'i', '8563', '3267', 'k', '6157', 'f']

SOLUTION: f, i, k, n, q, r, s, w, y

PROBLEM: ['j', 'v', '6675', '1335', '8155', '7803', 'd', 'z', '2727', '2711', 'm', '1877', 'n', 'q', '9181', 'c', '301', 'd', 's', 'u', '4187', '1427', 'h', 'e', 'v', '6085', 'h', '4709', 'l', '1773', '8247', '1021', 'm', 'n', 'g']

SOLUTION:
c, d, e, g, h, j, l, m, n, q, s, u, v, z