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: ['e', 'g', '2945', 'f', '4691', '2467', '375', '2925', 'z', '7787', 'm', 'j', 'e', '9867', '2429', '7579', '9283']
A: 
e, f, g, j, m, z