Whenever I try to run this code, I get this: java.lang.NullPointerException at com.codegym.task.task07.task0716.Solution.main(Solution.java:18) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) even though I never changed/edited CodeGym's original code. Why isn't this working?