diff --git a/src/backend/Simulator.java b/src/backend/Simulator.java
index 32eef87..ef512de 100644
--- a/src/backend/Simulator.java
+++ b/src/backend/Simulator.java
@@ -87,15 +87,29 @@ public class Simulator extends Thread {
 
 	private int countAliveNeighbors(int x, int y) {
 	    int count = 0;
-	    for (int i = x - 1; i <= x + 1; i++) {
-	        for (int j = y - 1; j <= y + 1; j++) {
-	            if (i >= 0 && i < COL_NUM && j >= 0 && j < LINE_NUM && !(i == x && j == y)) {
-	                count += grid[i][j];
+	    for (int i = -1; i <= 1; i++) {
+	        for (int j = -1; j <= 1; j++) {
+	            if (i == 0 && j == 0) continue; // Skip the cell itself
+
+	            int nx = x + i;
+	            int ny = y + j;
+
+	            if (loopingBorder) { // looping border
+	                if (nx < 0) nx = COL_NUM - 1;
+	                else if (nx >= COL_NUM) nx = 0;
+	                if (ny < 0) ny = LINE_NUM - 1;
+	                else if (ny >= LINE_NUM) ny = 0;
+	            } 
+	            else { // closed border
+	                if (nx < 0 || nx >= COL_NUM || ny < 0 || ny >= LINE_NUM) continue;
 	            }
+
+	            count += grid[nx][ny];
 	        }
 	    }
 	    return count;
 	}
+
 	
 	/**
 	 * method called at each step of the simulation
@@ -322,7 +336,7 @@ public class Simulator extends Thread {
 	}
 	
 	public void toggleLoopingBorder() {
-		loopingBorder =! loopingBorder;
+		loopingBorder = !loopingBorder;
 	}
 	
 	public void setLoopDelay(int delay) {