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.

['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']
d, k, u, w, z

['o', '1099', 'r', '8995', 'o', '2909']
o, r

['l', '4047', 'z', 'k', 'r', 'j', '5913', 's', '6901', '3485', '6515', 'l', 'c', 't', 'h', '1879', '445', 'n', 'i', '775', '737', '2765', 'u', 'm', '9999', 'v', 'w', '533', '1445']

c, h, i, j, k, l, m, n, r, s, t, u, v, w, z