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: ['2915', '6033', '5541', '4685', '1263', '6701', 's', '7269', 'g', '8033', '8171', '6917', 'l', '2913', '447', 'g', 'a', 'z', 'o', '7563', '5385', '5259', '5067', '4869', '2653', '6925', '7001', '8553', 'x', '1243', '9131', '5037']

Output: a, g, l, o, s, x, z


Input: Consider Input: ['d', '4377', '9271', '8053', '9519']

Output: d


Input: Consider Input: ['u', 'k', '8623', '9493', '6711', '9989', 'o', '1219', 'v', 'v', 'r', '1633', '2859', 'y', 't', '1121', '4803', 'p', '1229', '2469', '2407', 'y', '61', '6203', 'q', '4161', 'h', '9083', 'j', '503', '8767', 'c', '6419', 'j', '5989', 'x', 'p', 'a', 'c', '1557', 'l', '293', '6993']


Output: a, c, h, j, k, l, o, p, q, r, t, u, v, x, y