11/1    Straight hallway #1 makes an "L" intersection (90 degrees)
        with straight hallway #2. Hallway #1 is X feet wide and #2
        is Y feet wide. What is the longest board/plank/2x4
        that you can move from one hallway to the next, sqeezing
        around the corner?
        \_ Assume it's zero height (ie. it's a 2-dimensional problem)
        \_ How tall is the ceiling?
           \_ shorter than the shortest board
              \_ It still matters.  Should we just set ceiling height to zero
                 as the poster below has done?
        \_ Given ceiling height=0, I think the max length is (x+y)*sqrt(2)
           but don't ask me to prove it.  I might prove it later though...