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: ['1983', '1835', '6543', '6399', '4177', '9385', '7127', 'p', 'l', 'u', 'g', 't', '3423', 'g', 'b', 'l', '3133', '2429']

Output: b, g, l, p, t, u


Input: Consider Input: ['5971', 'x', 'c']

Output: c, x


Input: Consider Input: ['q', '9349', '7213', 'l', '2841', '4939', 'm', '2153', 'b', 'o', 'n', 'z', 'i', '1227']


Output: b, i, l, m, n, o, q, z