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: ['4641', '2881', 'c', '4827']

Output: c


Input: Consider Input: ['a', 'p', 'y', 'l', 'l']

Output: a, l, p, y


Input: Consider Input: ['m', 'k', '1069', '5901', 'j', '5695', 'f', '5251', 'z', 'e', '7851', 'm', 'z', '4587', 'm', '4507', '2905', 'g', 's', '3787', '4247', 'x', 'y', 'p', '1569', 'h', '2929', 'n', '1319', '7149', 'v', 'l', '293', '2451', '9163', 'k', '4149', '5807', 'j', '1073', '1581', 'c']


Output: c, e, f, g, h, j, k, l, m, n, p, s, v, x, y, z