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:
['5089', '6113', 'v', 'l', '5529', 'q', '7499', 'e', 'r', 'c', '5999', '2619', 'a', '2523', '7697', 'j', 'c', '6537', '8313', '5623', '4225', '7677', 'q', 'a', '6559', 'y', 'b', 'm', '7645', '7019', 'r', 'i', '5225', '703', 'i', '6189', 'f', 't', '7553']
answer:
a, b, c, e, f, i, j, l, m, q, r, t, v, y


question:
['d', '1989', '6365', 'y', 'm', '1245', '7539', 'm', '3787', '6987', 'e', 'e', 'y', '9577', 'b', '5', '8179', 'x', '2853', '6337', 'w', 'f', 'b', 'q', '563', '6077', '1133', 'x', '6045']
answer:
b, d, e, f, m, q, w, x, y


question:
['4777', '7547', 'j', '2087', '8295', 'k', '8761', '6669', 'f', 'v', 'f', '1295', '2861']
answer:

f, j, k, v