In men's basketball, the Rio Games are turning into the International Mathematical Olympiad.

At this point, a good calculator might be needed to sort out the standings.

All six teams in Group B are still alive for the quarterfinals heading into Monday, the final day of the preliminary round. Four of them will move on, though right now only Argentina and Lithuania have clinched quarterfinal spots.

Spain, Croatia, Brazil and Nigeria all have work to do.

"The pool play on the other side is incredible," U.S. coach Mike Krzyzewski said.

His team will face the No. 4 seed in the group, which won't be determined until after the three games: Nigeria-Brazil, Spain-Argentina and Lithuania-Croatia.

Tiebreakers could be involved, and if you want to see how they all work, go here and begin on page 72.

Things are easier in Group A, where the U.S., Australia, France are the top three and Serbia would be fourth with a victory over winless China.

The quarterfinals are Wednesday.