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: ['r', 'd', 'j', 'p', 'd', '2523', 'm', '7193', '2589', '7625', '8333', '3425', 'j', '1883', 'b', 'o', '385', 'd', '2791', 'y', 'a', '7071', 't', 'k', 'z', 's', '9553', '2687', '7665']
Student:
a, b, d, j, k, m, o, p, r, s, t, y, z