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: ['8489', 'h']

SOLUTION: h

PROBLEM: ['3117', 'i', 'd', '7537', 'i', 'q', '4649', '7263', '3655', 'd', 'x', '8569', 'g', '2389', '3933', '7099', '563', '3055', '9941', 'm', 'c', '3529', '3577', 'x', 's', 's', '6153', '1731', '9679', 'f', '8839', '5183', '5', '6433']

SOLUTION: c, d, f, g, i, m, q, s, x

PROBLEM: ['z', '681', 'h', '2307', '5017', '4171', 'z', 'j', '89', 't', '8591', '1847', '929', '5895', '1693']

SOLUTION:
h, j, t, z