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.

Ex Input:
['f', 'w', 'y', 't', '5269', '9989', 'p', 'v', '6609', 'v', 'c', 'q', 'm', '6565', '189', 'm', '3617', 'b', '9147', '665', 'v', '5989', '1511', '3123', '6667', '4661', '185', 'b', '3405', 'b', '6027', 'n', '6973', '505', 'g', '815', '3439', '2069', '291', 'j', 'f', '1121', '8009', 'm', '8353']

Ex Output:
b, c, f, g, j, m, n, p, q, t, v, w, y


Ex Input:
['277', '8697', 'q', '2023', '5723', 'm', '8673', 'f', 'z', 'z', 'a', '9875', 'p', 'x', 'l', 'z', 'x', '619', '6509', 's', '2067', '571', 't']

Ex Output:
a, f, l, m, p, q, s, t, x, z


Ex Input:
['u', '3173', '8907', '3471', 'x', 'r', '9783', '2397', '4751', 'y', 'u', 'r', 'u', '7811', 'o', '2873', '2571', '3573', 'p', '161', 'h', 'w', 'p', 'o']

Ex Output:

h, o, p, r, u, w, x, y