public int height(TreeNode node)
	{
		if(node.getLeft() == null){
			if(node.getRight()==null)return 0;
			return 1+ height(node.getRight());
		}
		if (node.getRight() == null){
			if(node.getLeft()==null)return 0;
			return 1 + height(node.getLeft());
		}
		return 1 + Math.max(height(node.getLeft()), height(node.getRight()));
	}