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: ['5181', '8651', '963', '2111', 'g', '7913', '8335', 'o', '1387', '9225', '6517', 's', 'r', '2291', '3699', 'y', 'y', '4223', 'i', '9109', 'm', 's', '8585', 'l']

SOLUTION: g, i, l, m, o, r, s, y

PROBLEM: ['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']

SOLUTION: a, e, i, n, p, q, r, s, t, u, x

PROBLEM: ['m', 'z', 'd', '4667', 'v', '2881', '887', 's', '9861', 'd', '8821', '125', 't', '4493', '6749', '2983', '309', '6033', 'i', '3421', 'j', '4001']

SOLUTION:
d, i, j, m, s, t, v, z

