I am see an Exception in thread "main" java.lang.StackOverflowError. I hope to know what is wrong with the code below. 

```
public void addWord(String word){
    addWord(word,root,0);
}

private void addWord(String word,Node root,int pos)
{
    for(Node c:root.children)
    {
        if(word.charAt(pos)==c.letter)
        {
            addWord(word,c,pos++);
        }
    }
    Node temp = new Node();
    temp.letter=word.charAt(pos);
    temp.children=new ArrayList<Node>();
    root.children.add(temp);
    if(pos==word.length()-1)
    {
        temp.terminus=true;
        return;
    }
    if(pos<word.length()-1)
    {
        addWord(word,temp,pos++);
    }
}

```