The list of senior Alex Zhai's accomplishments seems to grow daily: newly selected member of the US. Physics Team, two-time Math Olympian, etc. Now you can add "movie star" to that list. Well, sort of. Alex is one of six students featured in a new documentary titled "Hard Problems," which chronicles the 2006 U.S. IMO Team as it prepared for and competed in the 47th International Mathematical Olympiad.