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: ['k', '6595', '1595', 'v', 'h', 'b', '8815', '6681', 'j', '7581', 'p', '9095', '5453', 'r', 'y', '7755', 'x', '1853', 'k', 'q', 'u', 'j', 'q', '9651', 'o']

SOLUTION: b, h, j, k, o, p, q, r, u, v, x, y

PROBLEM: ['2165', 'f', '5081', 's']

SOLUTION: f, s

PROBLEM: ['h', 'e', '7883', '6985', '6499', '8943', '3487', 'x', '7091', 'w', '2753', 'g', '7249', '5641', 'h', '9701', 'z', '4749', '5609', '1283', 'a', '7649', 's', 'z', '6883', '1757', '2849']

SOLUTION:
a, e, g, h, s, w, x, z

