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: ['k', 'z', '303', 'a', 'f', 'q', 'i', '1475', '3453', 'd', 'w', '4037', 'z', 'h', 'k', '3547', '1561']

SOLUTION: a, d, f, h, i, k, q, w, z

PROBLEM: ['1135', 's', '2199', '3033', '9143', 'l', '7385', 'o', '1591', 'd', '7325', '5067', '6223', '3345', '8911', 'u', '6867', '6105', 'w', '875', 'r', 'g', 'y', 'w', 'q', '9283', 'j', 'v', 'w', 'h', '7415', 'a', 'h', 'm']

SOLUTION:
a, d, g, h, j, l, m, o, q, r, s, u, v, w, y