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.

Input: Consider Input: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']

Output: b, e, l, m


Input: Consider Input: ['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']

Output: g, h, k, l, o, t, y, z


Input: Consider Input: ['r', 'i', 'd', 's', 'b', 'z', 'y']


Output: b, d, i, r, s, y, z