How do I return root activity from Java code? (robot)

I am creating the following activities

Invalid Sign

When I click the button in D, I need to return to the home screen (i.e. a)

Anyone can advise me to do some code

resolvent:

Do you need to go to the Android home screen? That's another matter

However, if 'a' is the main activity of your application, you can use flag_ ACTIVITY_ CLEAR_ Top calls activity 'a'. This will clear all activities above 'a' and make the top of the stack