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: ['2583', 'w', '595', '6781', '9379', '3155', 'a', 'z', 'm', 's', '2871', 'f', '8015', 'f', 'v', '7405', 'd', 'z', 'z', '8153', '5385', '9547', '3197', 'q', 'e', '3305', 'y', '2949', '7007', 'p', '9145', '7267', 'y', 'z', 'c', 's', 'h', 'h', '4885', 'r', 'h', 'u', 'l', '9291']
Student:
a, c, d, e, f, h, l, m, p, q, r, s, u, v, w, y, z