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: ['4653', 'e', 'c', 'j', '6739', '3963', 'q', '4649', 'v', 's', 'j', '9757', '8075', '6253', '4365', 's', '9101', 'd', '6989', 't', '5687', '7389', '139', '4029', '5073', 'q', 'e', '2455', '1075', 'j', '1329', 'l', '4689', 't', 'z', '4179', 's', 'l', 'w', 'n', '6569', '8907', 'v', '605', 'y']

SOLUTION: c, d, e, j, l, n, q, s, t, v, w, y, z

PROBLEM: ['5293', '2211', 'r', 'j', 'x', 'y', 'u', 'n', 'r', 'l', 'v', '113', 'v', 'e', '1323', '6291', 'a', '7417', 'j', '4175', 'd', '855', 'z', '1123']

SOLUTION: a, d, e, j, l, n, r, u, v, x, y, z

PROBLEM: ['8989', '2997', '6225', 'v', '1285', 'b', '8325', '4229', '7193', '7761', 'e', '8149', 'i', '7273', 'o', '6449', '7413', '9107', 'z', '729', 'i', '6173', '2337', 'p', 'g', 'h', '9891', 'a', 'x', '7331', 'w']

SOLUTION:
a, b, e, g, h, i, o, p, v, w, x, z