public static int[][] x_y = {{-1, 0}, {-1, 1}, {-1, -1}, 
                                {1, 1}, {1, 0}, {1, -1},
                                {0, -1}, {0, 0}, {0, 1}};
    public static int maxRegion(List<List<Integer>> grid) {
        
        int max = 0;
        int[][] vis = new int[grid.size()][grid.get(0).size()];
        for (int i = 0; i < grid.size(); i++) {
            for (int j = 0; j < grid.get(0).size(); j++) {
                if(vis[i][j] < 1) {
                    int v = grid.get(i).get(j);
                    System.out.println("value: " + v);
                    if(v > 0) {
                        max = Math.max(bfs(grid, vis, i, j), max);
                    } else {
                        vis[i][j] = 1;
                    }
                }
            }
        }
        return max;
    }
    
    public static int bfs(List<List<Integer>> grid, int[][] vis, int start, int end) {
        
        int count = 1;
        Queue<List<Integer>> qu = new LinkedList<>();
        qu.offer(Arrays.asList(new Integer[]{start, end}));
        vis[start][end] = 1;
        
        while(!qu.isEmpty()) {
            List<Integer> a = qu.poll();
            int x = a.get(0);
            int y = a.get(1);
            for (int i = 0; i < x_y.length; i++) {
                int newx = x + x_y[i][0];
                int newy = y + x_y[i][1];
                
                if(newx >= 0 && newx < grid.size() && newy >= 0 && newy < grid.get(0).size() && vis[newx][newy] != 1) {
                    if(grid.get(newx).get(newy) > 0) {
                        qu.offer(Arrays.asList(new Integer[]{newx, newy}));
                        count++;
                    }
                    vis[newx][newy] = 1;
                    
                }
            }
        }
        
        return count;
    }