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: ['d', 'p', 'q', '5319', 'w', '4887', '6695', 't', '7711', 'l', '7597', 's', 'n', '1461', 'e', '9045', '1307', 'j']

SOLUTION: d, e, j, l, n, p, q, s, t, w

PROBLEM: ['9025', '3259', '4863', 'u', '6443', '9931', '627', 'x']

SOLUTION: u, x

PROBLEM: ['5351', '143', '73']

SOLUTION:
-1