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: ['x', 'o', '8161', 's', '3653', 'v', 'c', 'e', '5353', 'h', '9145', '333', 's', '7689', '8277', 'a', 'o', 'h', 'z', 'w', '9297', 'w', '9383', '8963', 'k', 'x', 's', 'w', 'h', 'j', '5737', 'o', '2247', '3723', '2043', '4615']

SOLUTION: a, c, e, h, j, k, o, s, v, w, x, z

PROBLEM: ['u', '9249', 'u', 't', 'm', 'm', 'n', 'w', '8617', '2729', 'i', 'l', '2971', '3227', 'b', '9017', '4711', 'i', 't', 'r', 'a', 'a', '1701', '6397', '4535', '9167', '6039', '6111', '849', 'p', '8197', '2645', '5147', 'u', 'l', '7419', 'w', 'w', 'k', 'x', 'c', '3377', '4015', '1297', 'f']

SOLUTION: a, b, c, f, i, k, l, m, n, p, r, t, u, w, x

PROBLEM: ['6427', 'e', 'o', 'h', 't', '2409', '5543', '3355', '2425', 's', '5315', 'h', 'm', 'p', '1827', 'r', '2027', '7027', '9049', '6947', '979', '2451', '7151']

SOLUTION:
e, h, m, o, p, r, s, t