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: ['o', '1217', '449', 'n', 'e', 'o', 't', '9043', '1925', '5687', '7197', '7943', 'u', '5053', 'q', 'e', '89', 'l', 'h', '3083', '4295', 'o', 'n', '6309', '743', 'n', 'j', '2105', 's', '6845', 'p', 'p', '1355', '3757', 'v', 'f', '961', '4623', '4633', 'p', '4593', 'p', '7337', 'o', 'u']

SOLUTION: e, f, h, j, l, n, o, p, q, s, t, u, v

PROBLEM: ['h', '1797', '8211', 'n', 'r', '7707', '2063', '4655', 'x', '5521', '8327', 'g', '7659', 'i', 'x', 'w', '9465', '4625', 'q', '5377', 'r', '225', 'r', 'i', 'e', '4163', 'g', 'g', '3537', 's']

SOLUTION: e, g, h, i, n, q, r, s, w, x

PROBLEM: ['3977', '517', '501', 's', '7377', 'z', 'r', 'u', 'g', '3481', '8057', 'g', '4345', 'h', 'u', 'f', '8467', 'd', 'z', 'o', '4073', 'g']

SOLUTION:
d, f, g, h, o, r, s, u, z