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.

['b', '2157', '7519', 'c', 'f', '8551', 'y', '8003', 'r', '3231', '1609', '8161', 'z', 'd', 'u', 'i', 'q', '8063', 'l', '3977', '7761', 't', '6993', '8631', 'i', '3941', '6313', '2467', 'b', '1421', 'h', '439', 't', '2699', 'w', 'u', 'o', 'x', 't', '7861', '9499', 'w']
b, c, d, f, h, i, l, o, q, r, t, u, w, x, y, z