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: ['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: ['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']

SOLUTION: a, c, d, f, g, j, k, m, p, t, w, x

PROBLEM: ['9507', '1177', '9839', '2935', 'o', '3203', 'm', 'f', 'c', '8893', '9751', 't', 'z', '6679', '1501']

SOLUTION:
c, f, m, o, t, z