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: ['8281', '4831', '1329', 'g', 'e', '8879', 'n', 's', 'x', 'j', '6305', 'j', '921', '3677', '5107', 'n', 'j', '9285', 'a', '5329', '6671', 'c', '9283', 'l', 'a', '7907', 'q', '7605', '855', '6477']

SOLUTION: a, c, e, g, j, l, n, q, s, x

PROBLEM: ['565', 'i', '615', '3047', 'm', '195', '7547', '3003', '9213', '9063', 'c', '5099', 'v', '5003', '9053']

SOLUTION: c, i, m, v

PROBLEM: ['3411', 'c', 'h', '317', '3445', 'w', 'u', '6575', 'w', 'l', 'z', '6355', '8433', '1349', 'b', 'r', '6143', 't', 'v', '9181', 'd', '339', '6365', 'q', 'g', 'b', '8579', '4559', '7927', '2903', '6669', '8471', '8609', 'e', '213', '3121', '539', 'u', 'e', '5151', 'm', 'x', '2221', '6509']

SOLUTION:
b, c, d, e, g, h, l, m, q, r, t, u, v, w, x, z