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: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

A: j, m, v, w, x
****
Q: ['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']

A: d, k, u, w, z
****
Q: ['z', 's', 'o', '7185', '4157', '7489', 'l', '7267', 'c', '443', 'w', '9393', '7715', '5579', 'a', '5313']

A:
a, c, l, o, s, w, z
****