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.

['v', '5433', 'v', '6749', '7491', 'i', 'm', 'e', '5815', '8423', '833', '7359', 'm', 'i', 'f', 'u', 'p', 'j', 't', '3171', '6165', 'q', 'a', '9475', 'm', 'q', '5995', '8443']
a, e, f, i, j, m, p, q, t, u, v

['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']
b, e, n, t, y

['v', 'e', '7123', '7691', '5699', 't', 'j', 'k', '751', '1659', 'u', '8521', 'h', '8481', '4113', 'c', 'a', 'h', '6139', 'q', '2409', '385', 'i', '9749', 'm', 't', 'p', 'o', 'r', 'c', 'q', '9787', 'p', '4849', '4497', '2337', '1343', '9971', 'b']

a, b, c, e, h, i, j, k, m, o, p, q, r, t, u, v