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: ['5957', 'd', 'i', 'b', 'e', '5565', 'c', 'i', '2919']

A: b, c, d, e, i
****
Q: ['e', 'c', '4241', '2685', 'o', '9859', 'z', '2647', 'b', 'c', 'y', '1985', '5985', '5709', '6655', 'q', 'z', '9933', '6817', '6477', '1837', 'x', 'p', '9251', '3787', 'v', '5741', 'e', 'p', '493', '5949', '5519', 'v', 'g', '1403', 'z', 'h', 'z']

A: b, c, e, g, h, o, p, q, v, x, y, z
****
Q: ['6437', 'y', '5923', '3403', '453', '9941', 't', 'c', 'h', '9821', 's', '8375', '7595', '5133', '5325', '1127', '1375', '1191', 'j', '3319', '9233', '5215', 'm', '8851', '3973', '377']

A:
c, h, j, m, s, t, y
****