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: ['q', '9033', 'p', 'z', '1743', '247', '967', '445', '9849', 'f', '9113', 'b', 'g', '6041', 'j', '927', 'i', 'p', '6821', 'q', '6701', 'f', 'j', 'o', 'y', 'c', '7981', 'b']

SOLUTION: b, c, f, g, i, j, o, p, q, y, 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: ['5133', '1705', 'o', '2721', '17', '7763', '1983', 'j', '5889']

SOLUTION:
j, o