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: ['t', 'm', '7071', 'j', '353', 'n', 'a', 'm', '9211', 'i', '9537', 'q', '7669', '869', '8753', '8071', '375', '9971', 'c', 'n', '5851', 'u', '2491', '2697', '2789', '4683', '879', 'q', 'g', 'p', 'd', 'x', 'r', 'i', '8171', '5449', '2477', '1151', 'z', '3845', '1079', 'j', 'n', 'p', '8199']

SOLUTION: a, c, d, g, i, j, m, n, p, q, r, t, u, x, z

PROBLEM: ['v', 'd', '3805', '8031', '3327', 'c', 'n', '6153', '2705', 'w', '5675', '6543', 'm', 'v', 'y', 'd', '2943', '4423', '515', '4501', 'y', '9377', 'j', 'i', 'f', '4749', 'o', 'r', '2605', 'm', '117', 'o', '9197', 't', 'l', '4145']

SOLUTION: c, d, f, i, j, l, m, n, o, r, t, v, w, y

PROBLEM: ['5923', 'z', '3527', 'k', '627', '8305', 'g', 'q', 'n', 'w', '2571', '9369', 's', 'h', 'h', 'i', 'i', '8311', '3561', '1925', '4521', '7661']

SOLUTION:
g, h, i, k, n, q, s, w, z