Hello - Forgive me if this is a "basic" question but all my Mileage Runs have been domestic. Looking at going from ORD to SIN via NRT on UA. When you get to SIN - there would be about a 6-7 hour layover if one was to fly right back. If one was to turn right back would you have to clear customs in SIN or would this be done in NRT before heading back to ORD? Has anyone ever done that (or do most spend a day or so there) and what was their experiences? Thanks!