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: ['m', '5005', 'y', 'h', 'w', '3609', 'p', '2539', '3307', 'p']

Answer: h, m, p, w, y


Question: ['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']

Answer: a, b, d, e, h, i, j, m, o, q, r, t, u, v, y


Question: ['w', '4335', 'l', '9761', 'f', '1083', 'z', 'k', '1929', '1845', 'g', 'm', 'i', '459', '87', '5797', '4919', 'l', '3597']

Answer:
f, g, i, k, l, m, w, z