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: ['9923', 'x', '1901', 'v', '1459', '7503', '3829', '4929', 'k', 'c', '3329', '8793', 'n', 'a', '7249', 'b', 'l', 'l', 'm', 'p', 'b', 'a']

Output: a, b, c, k, l, m, n, p, v, x

Input: Consider Input: ['p', '2923', 'e', 'k', '5433', '605', '5079', 'k', 'p', 'x', '4845', '4099', '6795']

Output: e, k, p, x

Input: Consider Input: ['8859', '667', '5581', '5063', 'o', '7029', '6571', 'x', '4343', 't', '1471', 'i', 'f', '1263', '8319', '4629', 't', 'j', 'd', '495', 'u', 's', 'u', '911', '2843', '1383', '6393', '3773', '9473', 'v', '3839']
Output: d, f, i, j, o, s, t, u, v, x