class TrieNode:
    def __init__(self):
        self.children={}
        self.isword=False


class WordDictionary:

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.root=TrieNode()

    def addWord(self, word: str) -> None:
        """
        Adds a word into the data structure.
        """
        if not word:
            return

        node=self.root
        for c in word:
            if c not in node.children:
                node.children[c]=TrieNode()
            node=node.children[c]
        node.isword=True

    def search_helper(self,node,word)->bool:
        if not node or not word:
            return False

        for i in len(word[i]):
            if word[i]=='.':
                for child in node.children.values():
                    if self.search_helper(child,word[i+1:]):
                        return True
            else:
                if c not in node.children:
                    return False
                node=node.children[word[i]]
        return node.isword

    def search(self, node, word) -> bool:
        """
        Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter.
        """
        return self.search_helper(self.root,word)



# Your WordDictionary object will be instantiated and called as such:
# obj = WordDictionary()
# obj.addWord(word)
# param_2 = obj.search(word)