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: ['j', 'r', 'z', 'f', '1485', '2419', 't', 'd', '6023']

SOLUTION: d, f, j, r, t, z

PROBLEM: ['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']

SOLUTION: b, i, k, u, z

PROBLEM: ['6157', '531']

SOLUTION:
-1