int count(int i, Trie *head, std::string &key)
{
    if(i == key.size()) return 0;
    if(head->is_leaf || head->nodes > 1) return 1 + count(i+1, head->character[key[i] - 97],key);
    else return count(i+1, head->character[key[i] - 97],key);
}