findGoodEdges :: Board -> [Edge] -> IO [Edge]
findGoodEdges b le = return (filter (not . isEdgeN 2 b) le)
findGoodEdges :: Board -> [Edge] -> IO [Edge]
findGoodEdges b le = return (filter (not . isEdgeN 2 b) le)
findGoodEdges b le = return (filter (not . isEdgeN 2 b) le)