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.

['8879', 'x', '1383', '4925', '2867', 'j', 't', 'e', 'w', 'p', 't', 'w', 'l', '7447', '1877', '7747', 'k', 'b', 'x', '8565', 'q', '8575', '5711', '2949', '5637', '2197', '4905']
b, e, j, k, l, p, q, t, w, x

['e', '8391', '7065', '6141', '3335', 't', 'i', 'c', '1791', '6333', 'b', 'z', '1621', 'e', 'h', 'u', 'o', 'q', '3195', '6507', '3253', 'c', '2067', '3917', '7111', 'r', 'j', 'd', '3987', '9139', 'm', '981', 'l', 'f', '2417', 'w', '9983', 'h', 'd', '6021', 'a', 'f']
a, b, c, d, e, f, h, i, j, l, m, o, q, r, t, u, w, z

['l', '4293']

l