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: ['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']

Output: a, n, u


Input: Consider Input: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

Output: j, m, v, w, x


Input: Consider Input: ['1179', '7505', 'v', '1281', '147', '9957', '8633', 'u', '349', 'c', 'h', '1607', '6811', 'w', 'q']


Output: c, h, q, u, v, w