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: ['l', '7111', 'd', 'e', 'h', 'z', 'x', '5673', 'v', '8255', 'i', 'z', 'c', 'i', '4287', 'q', '9293', '9137', 'p', 'n', 'o', 'n', '7883', '6453', '7355', '8769', 'y', '9153']

SOLUTION: c, d, e, h, i, l, n, o, p, q, v, x, y, z

PROBLEM: ['w', 'a', 'm', 'd', '409', 'm', 'v', 's', '7801', 'l', '8551', 'k', '867', 'n', '7731', 'z', '3773', '9137', 'v', 's', 'p', 'p', 'f', 'z', 'g', 'q', 'g', '877', '697', '2057', '8389', '2399', '5263', '2761', '9841', '1781', 'l', '8023']

SOLUTION: a, d, f, g, k, l, m, n, p, q, s, v, w, z

PROBLEM: ['513', '659', 'j', '2097', '4497', '5987', '9711', '3105', '5507', '8785', '4147', 'u', 'y', '6047', 'y', '5169', 'j', '849', 'h', 't']

SOLUTION:
h, j, t, u, y