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.

['6143', 'y', '5505', '9813', 'r', 'v', 'u', '8681', '2387', 'u', 'o', 'm', '9793', 'm']
m, o, r, u, v, y

['n', 'h', 'h', 'e', 'p', '1265', '4853', '9433', '1227', '1619', '6381', 'o', '8285', 'k', 'u', '7471', 'm', '6887', '6579', '5813', '5563', '8535', 'n', '3743', 'h', 't', '4497', '2791', 'e', 'v', '6769', '7969', 'x', 't', 'x', 'q']
e, h, k, m, n, o, p, q, t, u, v, x

['2349', '8593', '1093', '4191', 'x', '987', '8223', '5649', '2057', 'f', 'f', 'w', 'k', 'h', '7035', 'w', 'v', '2675', 'v', 'j', '1037', '3753', '8601']

f, h, j, k, v, w, x