Teacher: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.
Teacher: Now, understand the problem? Solve this instance: ['j', 's', 'n', 'r', 'a', '7675', '9261', 'b', '6679', 'f', '9007', 'l', '2029', 'l', '6745', 's', 'p', 'a', 'f', '8351', 'n', 'h', '4599', '3195', 'j', '4367', '3605', '7753']
Student:
a, b, f, h, j, l, n, p, r, s