diff --git a/day18/day.go b/day18/day.go
index c024ba5..baba46f 100644
--- a/day18/day.go
+++ b/day18/day.go
@@ -4,20 +4,15 @@ import (
 	"tools"
 )
 
-type coord struct {
-	x int
-	y int
-}
-
-func play(grid tools.ToggleGrid, stuckCorners bool) {
-	neighbours := make(map[coord]int)
-	for thisCoord := range grid.GetOnCoordinates() {
+func play(grid tools.GridToggle, stuckCorners bool) {
+	neighbours := tools.NewGridInt()
+	for _, thisCoord := range grid.GetCoordinates() {
 		for cx := thisCoord.X - 1; cx <= thisCoord.X+1; cx++ {
 			for cy := thisCoord.Y - 1; cy <= thisCoord.Y+1; cy++ {
 				if cy == thisCoord.Y && cx == thisCoord.X {
 					continue
 				}
-				neighbours[coord{cx, cy}]++
+				neighbours.Add(cx, cy, 1)
 			}
 		}
 	}
@@ -25,20 +20,20 @@ func play(grid tools.ToggleGrid, stuckCorners bool) {
 	for x := 0; x <= grid.MaxX; x++ {
 		for y := 0; y <= grid.MaxY; y++ {
 			if grid.State(x, y) {
-				if neighbours[coord{x, y}] != 2 && neighbours[coord{x, y}] != 3 {
+				if neighbours.Value(x, y) != 2 && neighbours.Value(x, y) != 3 {
 					if !stuckCorners || !grid.IsCorner(x, y) {
 						grid.Set(x, y, tools.Off)
 					}
 				}
-			} else if neighbours[coord{x, y}] == 3 {
+			} else if neighbours.Value(x, y) == 3 {
 				grid.Set(x, y, tools.On)
 			}
 		}
 	}
 }
 
-func makeGridFromInput(input []string) tools.ToggleGrid {
-	grid := tools.NewToogleGrid()
+func makeGridFromInput(input []string) tools.GridToggle {
+	grid := tools.NewGridToggle()
 	for y, line := range input {
 		for x, c := range line {
 			if c == '#' {