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.

['6235', 'g', '8869', 'k', '2631', 'j', 'r', 'e', 'z', '1129', '6131', '4061', 'g', 'c', 'z', '4365', '9297', 'b', 'u', 'j', '2601', 'p', '8227', 'i', 'e']
b, c, e, g, i, j, k, p, r, u, z