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: ['z', 'l', 's', 'f', 'j', 'x', '1125', 'd', '37', '5009', '9187', 'b', '8683', '8841', 'y', '9955', '1571', 'm', '347', '3679', '5797', '2133', 'g', 'u', '9817', '6347', '2067', '1927', '167', '4215', '45', 't', 'd', '6599', '4751', 'g', 'l', 'u', '7881', 's']

SOLUTION: b, d, f, g, j, l, m, s, t, u, x, y, z

PROBLEM: ['895', '2049', '8839', '1773', 'v', '467']

SOLUTION: v

PROBLEM: ['2643', '1571', '4613', 'j', 'm', 'h', '3395', 'p', '6831', 's', '4369', '2845', 'k', 'e', 'e', '1915', 'w', 'x', 'w', '1741', 'p', '3757', 't', 'y', 'q', 'a']

SOLUTION:
a, e, h, j, k, m, p, q, s, t, w, x, y