At the end of your code, call .find() on alphabet and pass 'z' as the argument to the method.
First, hit Reset to restore the starting code for this step.
Then, simply use the find method on alphabet, with ‘z’ in the parentheses.
You’ve done this in your code already but you don’t need to declare a variable (argument). An argument is just the name for a value which is passed to a method or function when it is called (i.e. ‘z’ in this case).