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.

['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']
b, i, k, u, z

['5761', '2289', '577', 't', '125', 'i', 'g', '9693', '747', 'd', '4829', '9587', 'f', 'k', 'w', 'v', '8607']
d, f, g, i, k, t, v, w

['1953', 'w', '2049', 'f', 'i', '2105', '8469', '5783', 'y', '6095', '8705', '9365', 'v', 'f', 'e', 'i', 'k', '9509', 'r', 'i', '1651', '3147']

e, f, i, k, r, v, w, y