From 0 to 5 the Difficulty Level for completing this task is 0. It all boils down to dotting your Gmail username which is also your Gmail email address to trick Twitter. For Google these Gmail email addresses (for example) are the same, they belong and refer to the same person; firstname.lastname@example.org, email@example.com, or firstname.lastname@example.org.
Because Gmail doesn’t recognize dots as characters within usernames, you can add or remove the dots from a Gmail address without changing the actual destination address; they’ll all go to your inbox, and only yours.
For Twitter no. For Twitter they are not classentical, for Twitter these email addresses belong to three different persons. So by adding a dot or dots(.) to your Gmail email address (like above), you can re-use your Gmail email addresses to register other Twitter accounts -- intanto all your emails from Twitter will end up in the same Gmail inbox.