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.

Q: ['w', '1367', '5389', '9515']

A: w
****
Q: ['o', 'z', 'h', '3965', 'n', '3009', '173', '997', '3987', '5799', '2331', 'p', 'x', '897', '8213', '451', 'u', 't', 't', '9917', '4501', 't', 'c', 'i', 'w', 'w', 'u', '2977', 't', 'b', '4161', '9281', 'w', 'f', '3137', '5745', 'e', '673', '6363', 'h', 'q', 'x', 'm', '9505']

A: b, c, e, f, h, i, m, n, o, p, q, t, u, w, x, z
****
Q: ['307', 'p', '9011', 'k', 'k', '7589', 'k', 'y', '935', '4013', 'v', 'y', '3917', '267', 'n', 'r', 'f', 'p', '1071', '2965', 'f', '5797', 'r', 's', '2115', 't', '8267', 'r', 'e', 'x', 'n', 'u', 'c', '1151', 'd', '1479', '9375', '207', '4807', 'm']

A:
c, d, e, f, k, m, n, p, r, s, t, u, v, x, y
****