private static Node constructTree(LinkedList<Integer> level) {
	Queue<Node> q1= new LinkedList<>();
	Queue<Node> q2= new LinkedList<>();


	/*
	 * Insert first element in queue 1
	 * Insert next two elements in second queue
	 * */

	Node mainRoot=new Node(level.poll(),null,null);
	q1.add(mainRoot);
	q2.add(new Node(level.poll(),null,null));
	q2.add(new Node(level.poll(),null,null));

	while(!q1.isEmpty() && !q2.isEmpty()) {

		Node root=q1.poll();
		Node left=q2.poll();
		Node right=q2.poll();
		q1.add(left);
		q1.add(right);

		root.left=left;
		root.right=right;

		/*
		 * Insert next two elements in second queue
		 * */
		if(!level.isEmpty()) {
			q2.add(new Node(level.poll(),null,null));
			q2.add(new Node(level.poll(),null,null));
		}
	}
	return mainRoot;
}