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', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']

SOLUTION: e, g, j, l, n, q, r, s, t, v, x, y, z

PROBLEM: ['4371', '9499', 'e', 'w', '9969', '8367', '2897', '1745', 'i', '7049', '9773', 'h', '9649', 'u', '4673', '8513', '8547', 'z', '1995', '7739', '2215', '171', 'c', '7527', '2479', 't', '5223', 'p', '2313', '3243', '2281', 'r', 'c']

SOLUTION: c, e, h, i, p, r, t, u, w, z

PROBLEM: ['7555', '6891', '781', '5861', '671', '1947', '2569', '8783', '8031', 't', 'o', '7657', '8581', 'v', 'r', '4625', 's', 'h', '4937', 'l', '5647', '9155', '7917', '4725', '2281', '7585', 'c', '1447', '2437', '1583', 'd', '1305', 'j', '8119', 'c', 'b', '1713', 's', '783', '9289', 'z', '2241']

SOLUTION:
b, c, d, h, j, l, o, r, s, t, v, z