2 

     2 

     3 //type Pos = (Int, Int)

     3 //type Pos = (Int, Int)

     4 //type Path = List[Pos]

     4 //type Path = List[Pos]

     5 

     5 

     6 def add_pair_urban(x: Pos)(y: Pos): Pos = 

     6 def add_pair_urban(x: Pos)(y: Pos): Pos =