class trie_node(object):
    def __init__(self):
        self.node = {}
        self.count = 0

    def insert(self, word):
        curr = self
        for c in word:
            if not curr.node.get(c, None):
                new_node = trie_node()
                curr.node[c] = new_node
            curr = curr.node[c]
        curr.count += 1

    def query(self, word):
        ret = 0
        curr = self
        for c in word:
            if not curr.node.get(c, None):
                return ret 
            curr = curr.node[c]
            ret += curr.count
        return ret