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: ['587', '3903', 'z', 'l', 'k', '5693', 'x', '1695', 'c', '3185', 'g', '9491', '8185', '1285', '2533', '6825', '3187', '6039', 'e', '251', 'w', '7741', '9573']

Answer: c, e, g, k, l, w, x, z


Question: ['d', '771', '4193', 'e', '1537', 'a', 'q']

Answer: a, d, e, q


Question: ['1429', '3027', 'e', '493', 'v', '8141', '5597', 'e', 'd', '8395', '5947', '559', '8195', 'f', '7271', '1183', '1167', 'k', '829', '9403', 'r', 'y', '7315', '5295', 'a', '4389', 'q', '7523', 'j', '9183', '3727', 'f', 'a', '3259', '4271', '4353', '845']

Answer:
a, d, e, f, j, k, q, r, v, y