instruction:
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.
question:
['d', '5285', 'z', 't', 'i', '719', 'z', 'b', '3603', '4781', 'o', 'g', 'j', 'd', 'r', 'a', 'x', '5829', '4907', '7395', '993', '2109', '1745', '415', '7525', '1029', '7791', '5321', 'h', '6391', 'g', '4613', '9191', 'o', '7365', '1811', '9695', 'w']
answer:
a, b, d, g, h, i, j, o, r, t, w, x, z


question:
['y', 'g', '107', '4899', '6357', '9777', 'k', '1865', '7029', 'q', 'x', '7051', 's', '6125', '4285', '2731', 'z', 'a', '737', '6137']
answer:
a, g, k, q, s, x, y, z


question:
['7563', '481', '4451', '6851', 'b', '1265', '559', '4281', 'h', 'i', '3423', '223', 'v', '6125', '4601', '323', 'b', '5237', '4503', 'z', '9653', '1875', '6975', 'r', 'j', '7997', '4079', '6053', '6139', '1277', 'i', '7761', '8041', 'i']
answer:

b, h, i, j, r, v, z