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: ['k', '1995', 'b', '2581', 'x', '2639', 'i', '6761', '2701', 'd', '6993', '9375', 'r', 'm', '249', '8115', '8179', 't', '4901', 'i', '6197', '2809', 'e', 's', 'j', '4261', 'f', '6649', '7527', '3839', '5651', '9287', 'n', '2505', 's', 'q', '2825', 'g']

SOLUTION: b, d, e, f, g, i, j, k, m, n, q, r, s, t, x

PROBLEM: ['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']

SOLUTION: c, d, l, m, n, v

PROBLEM: ['275', '3023', '1195', 'g', '6015', '4891', 'p', '3367', '7161', '9099', 'g', 'o', '1019', '2893', '9215', 'o', 'd', '7765', '7675', 'g', 'h', '9453', '9473', 'e', '2475', 'h', '3631', 'p', '1597']

SOLUTION:
d, e, g, h, o, p