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.

['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']
f, k, n, p, q

['3627', '2051', '3203', 'c', 'r', 'a', '1453', 'e', 'z', 't', '1093', '4651', 'a', 'f', '8159', '9623', 'l', 't', 'r', '6963', '7071', '8103', '3493', 'y', '2369', '609', '2011', 'f', '187', 'f', 'c']
a, c, e, f, l, r, t, y, z

['7805', 'a', 'e', '3847', '7325', '1459', 'c', '7307', 'w', '9203', 's', 'u', '9009', 'j', '23', '8113', 'q', '5265', '9663', '3047', '3239', '1069', '7251', '4793', 'u', 'g', 'q', 'o', 'y', 'h', 'g', 'b', 's', '7307', 'v', '9383', '1491', 'o', 'e', '1785', '8399', '699', '9937', '1199']

a, b, c, e, g, h, j, o, q, s, u, v, w, y