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: ['p', 'k', 'i', '753', 'u', 'm', '3817', '1597', 'l', 'm', 'a', 'i', 'b', 's', 'c', '2561', 'x', '5363', '1173', '8657', '2033', 'b', 'p', '3093', 'k', '6535', '307', '9925', 'b', 'q', 'q']

SOLUTION: a, b, c, i, k, l, m, p, q, s, u, x

PROBLEM: ['9351', 'v', 'h', 'z', 'g', 'f', 't', 'q', 'g', 'o', '4073', 'n', '6149', '1735', '157', 'm']

SOLUTION: f, g, h, m, n, o, q, t, v, z

PROBLEM: ['j', '5355', 'w']

SOLUTION:
j, w