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: ['7065', 'f', 'k', 'i', 'd', '8291', 'z', 'e', 'q', '5345', 'h', '3397', 's', '5355', 's', '9033', 'e', '5241', '5285', 'm', 'h', 'i', 'n', '6471', '3365', 'f', 'r', '6145', 't', '4869']

SOLUTION: d, e, f, h, i, k, m, n, q, r, s, t, z

PROBLEM: ['f', '217', '449', 't', 'j', '4097', '5561', '8317', '647', 'u', 'b', '7833', 'r', '9011', 'z', '2753', '2183', 'z', 'o', 'g', '7541', 'b', '8795', '327', 'v', 'e', 't', 'l', '4909', 'k', '7681', 'r']

SOLUTION: b, e, f, g, j, k, l, o, r, t, u, v, z

PROBLEM: ['4251', '4855', 's', 't', 't', 'z', 'r', '1611', '5453', 'x', '275', 'p', 'n', 'u', '693', '9235', '8703', '6625', '7041', '6329', 'l', 'a', '2419', '473', '77', 'j', '6747', '4243', '9027', 'l', '4283']

SOLUTION:
a, j, l, n, p, r, s, t, u, x, z