instruction:
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.
question:
['3019', 'g', 'q', 'u', '611', 'z', '3671', '8119', '1679', 'h', '2631', '655', 'k', '2837', 'e', 'f', 'e', 'f']
answer:
e, f, g, h, k, q, u, z


question:
['j', 'a', 'z', 'h', '4129', '4159', 'm', 'o', 'o', '1193', '2905', '3083', 'q', 't', 'm', 'o', '673', '7547', 'n', 'c', 'r', 't', '2897', '4959', 'z', '2377', 'y', '7977', 'u', 'b', 's', 'w', 'e', 'd', '8051']
answer:
a, b, c, d, e, h, j, m, n, o, q, r, s, t, u, w, y, z


question:
['5577', 'i', '8601', 'r', '6311', '5387', 'o', '1157', 'j', '5099', '3457', '9075', 't', 'x', '3447', 'j', '9525', 'u', 'h']
answer:

h, i, j, o, r, t, u, x