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: ['y', 'i', '257', '3695', 's', '6717', '4817', '4117']

A: i, s, y
****
Q: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

A: b, c, e, f
****
Q: ['w', '2505', 'j', 'c', '4915', '7763', '5941', 'm', 'a', '8365', '3325', 'y', '6071', 'p', 'q', '4959', 'l', '2275', '1201', 'c', '7787', 'd', 'f', '8521', 's', '1405', 'f', '6397', 's', '3031', '3117', 'i', 'w', 'k', 'q', 'r']

A:
a, c, d, f, i, j, k, l, m, p, q, r, s, w, y
****