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: ['8821', '9833', 'l']

Output: l


Input: Consider Input: ['163', 'x', 'g', '5997', 'm', 'l', '7225', '7907', '375', 'y', 'a', 'j', 'c', 'j', '7755', '147', 'h', '3845', 'y', 's', 'h', 'u', '8737', '6091', 'j', 'f', 'c', '7395', '881', '1771', 'y', '3691', 'h']

Output: a, c, f, g, h, j, l, m, s, u, x, y


Input: Consider Input: ['7031', '2247', 'l', 'c', 'c', '6645', 'f', '6283', 'v', 'n', '4797', 'y', '1511', '7231', 'y', '5919', '1037', 'c', 'p', '329', 'o', '7907', '2699', '2743', '9493']


Output: c, f, l, n, o, p, v, y