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: ['g', '6867', '7965', '3313', 'k', '1827', '7337', 'u', '1209', '5145', 'w', 'h', '9059', 'u', 'b', '3189', '2837', 'k', 'y', 'e', 'b', '4479', '541', '7103', 'h', 'm', '2177', '6377', '3993', '7167', 'q', '2145', '5007', '9135', '5331', 'e']

SOLUTION: b, e, g, h, k, m, q, u, w, y

PROBLEM: ['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']

SOLUTION: e, l, n, p, q, r

PROBLEM: ['5881', '165', 'y', 'c', '7719', '9551', 's', 'l', 'x', 'm', '4137', '7563', '819', 'v', 'k', 'z', 'p', '6137', '7403', '9829', '4327', '9051', 'k', 'j', 'h', 'j', '1767', '7955', 'x', 'o', 'b', '3295']

SOLUTION:
b, c, h, j, k, l, m, o, p, s, v, x, y, z