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.

['887', 'p', '3819', '2727', '1407', 'b', 'n', '737', 'd', 'w', 'q', '6877']
b, d, n, p, q, w

['o', '369', 'z', '5721', 'w', 'v', '4973', '7773', 'k', '3071', '5103', '425', '4239', '7977', 'n', 'i', 'k', '8117', '9843', 'n', 'd', '1353', 'h', 'd', 'v', 'z', 'j', '8727', '6997', 'x', '767', '4331', 't']
d, h, i, j, k, n, o, t, v, w, x, z

['s', '2335', '2379', 'h', '9083', 'c', '8791', 'o', '2489', '9947', 'l', 'g', 'm', 'u', '5093', '7355', 'k', '1915', '9813', 'q', 'o', 'w', '4741', '1609', '8843', '2941', '3485']

c, g, h, k, l, m, o, q, s, u, w