dialogue: Izzy: Anyone knows where professor Xavier has his duty hours?
  Lily: I think on the 2nd floor
  Mark: 2nd? I think his office is in statistics department
  Lily: So 3rd floor?
  Mark: That's my guess, I think to the right from the elevator, but don't know the number
  Lily: Just try names on the doors 
  Izzy: So statistics, 3rd floor, gotcha! 
  Izzy: You guys are awesome!
summary: Professor Xavier probably holds his duty hours on the 3rd floor in the Statistics Department. 