Create Simple Application to Highlight Duplicate Emails

We are looking to build a quick application utility. The application will help identify email addresses that exist in two separate lists. The app will have two columns. We will paste email addresses into each column (note: around 500,000 addresses will be used). The app will then produce a third text box, which will show any email addresses which appear in BOTH boxes (ie, duplicates). The email check is not case-sensitive. This is a very simple, easy application. It can be built in Access, Visual Basic, C#, whichever you feel most comfortable with. It should also be relatively quick -- not taking more than a few minutes to process this simple task. This is a quick and easy job for someone who is just starting on Freelancer! :-) Start your response with YOLO to ensure you've read this, and so we know who's best suited to this project!