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: ['c', '7039', 'g', '1899', 'r', '507', 'c', '2587', '3865', '1729', '3927', 'r', '3535', '2791', 'm', 'l', 'r']

Output: c, g, l, m, r


Input: Consider Input: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

Output: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y


Input: Consider Input: ['s', '1039', '6529', '8981', 'u', '3753', 'r', '159', '5027', 'y', 't', '2915', '4009', 'z', 'y', '497', '9927', 'r', 'p', 'n']


Output: n, p, r, s, t, u, y, z