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: ['5161', 'v', 'y', '6005', 'y', 'l', '5451', 'z', 'j', 'd', '4597', '9319', '1241', 'g', 'f', 'b', 'g', '683', '763', 'm']

A: b, d, f, g, j, l, m, v, y, z
****
Q: ['9483', '501', 'j', 'k', '3103']

A: j, k
****
Q: ['9493', '7781', 'x', '8129']

A:
x
****