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: ['t', 'x', '1699', '8727']

A: t, x
****
Q: ['l', '1213', 'm', 'k', '7825', '3501', '2397', '2313', 'v', '4119', 'h', 't', '6137', 'l', '9851', 'q', '9661', 'b', 'z', '1437', '1759', 'l', '611', '5085', '4443', 'n', 'u', 'b', '2511', '6023', '7157', 'n', '9921', 'o', 'a', 'o', 'w', 't', 'o', '1607', '6751', 'n', 'b']

A: a, b, h, k, l, m, n, o, q, t, u, v, w, z
****
Q: ['9589', 'n', 'z', 'j', '3105', 'x', '7217', 'c', '7549', '4453', '9101', '47', '3913', '8425', 'z', '4695', '31', 'x', 'x', '2933', 't', '6445', 'c', '5601', 'i', 'f', 'i', '8111', 's', 'n', '9675', 'z', '4347', '8467', 'n', '3401', '4609', '3557', '2687', '6491', '5823']

A:
c, f, i, j, n, s, t, x, z
****