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: ['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']

SOLUTION: g, i, j, l, o, p, q, r, v

PROBLEM: ['f', '3409', 'i', '4147', '1745', '6007', 'l', 'd', 'i']

SOLUTION: d, f, i, l

PROBLEM: ['r', 'y', '9297', '7047', '1131', '9585']

SOLUTION:
r, y

