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: ['7073', 'd', 'e']

Answer: d, e


Question: ['789', '3603', '3517', '5831', 'z', 'q', 'w', 'l', '5701', '9503', '8169', '1123', 'e', '529', 'j', 'z', 'l', 'o', '3705', 'o', '5131', '6063', 'c', 'j', '6275', '7701']

Answer: c, e, j, l, o, q, w, z


Question: ['u', '8129', 'v', 'a', '7737', 'u', '1469', '2419', 'a', 'f', 'w', '6867', '7003', 'o', '6211', '5273', '3349', '7337', 'i', 'a', 'y', '489', 'f', '763', 't', 'd', 'h', '1409', '7155', 't', '2475', 'l', '7981', 'o', '3505', 'k', '1971', '5075', '9843', 'd']

Answer:
a, d, f, h, i, k, l, o, t, u, v, w, y