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: ['9425', 'l', 'c', 'n', '5925', '2543', '3935', 'c', '7533', 'j', 'q', '3775', '5897', '9435', '69', 'e']

SOLUTION: c, e, j, l, n, q

PROBLEM: ['h', '1797', '8211', 'n', 'r', '7707', '2063', '4655', 'x', '5521', '8327', 'g', '7659', 'i', 'x', 'w', '9465', '4625', 'q', '5377', 'r', '225', 'r', 'i', 'e', '4163', 'g', 'g', '3537', 's']

SOLUTION: e, g, h, i, n, q, r, s, w, x

PROBLEM: ['h', '2279', 'y', 's', '8231', 'e', '4203', 'g', '6011', '5991', '4401', '4279', 't', 'q', 'x', 'e', '3179', 'j', '8841', '679', '8113', 'y', 'w', 'v', 'q', 'o', '9919', '8193', '7199', 'f', 'm', '3889', '8225', 'c', '1299', 'm']

SOLUTION:
c, e, f, g, h, j, m, o, q, s, t, v, w, x, y