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: ['491', '229', 'g', '6677', '4793', 'h', 'x', 'a', '2333', 'u', 'l', '785', 'p', '7331', '653', '5193', '5415', '8417', 'v']

A: a, g, h, l, p, u, v, x
****
Q: ['j', '425', '6223', '6631', 'y', '7649', 'r', 'a', '7933', '7947', 'l', 'l', '8755', 'g', 'b', '3351', '49', 'v', 'm', 'x', '3291', '1007', '1401', 'z', 'q', 'a']

A: a, b, g, j, l, m, q, r, v, x, y, z
****
Q: ['987', 'k', '5351', 'd', 'j', 't', 'l', 'o', 'g', '4655', '3213', 'd', 'm', 'r', '5877', '7739', 'l', '6325', 'l', '4977', 'y', '1089', 'b', 'x', '9959', 'u', 'm', '7371', '1287', '933', 'h', '1187']

A:
b, d, g, h, j, k, l, m, o, r, t, u, x, y
****