class Trie{

    public:
    Trie *childNodes[10];
    int wordCount;

    Trie(){
    for(int i=0;i<10;i++){

        childNodes[i]=NULL;
    }
    wordCount = 0;
    }

};

bool insert_key(Trie *root, string key_word){

Trie *currentNode = root;

for(int i=0;i<key_word.size();i++){
    int index = key_word[i]-'a';

    if(currentNode->childNodes[index]==NULL){
        Trie *newNode = new Trie();
        currentNode->childNodes[index]= newNode;
    }
    else{
        if(currentNode->childNodes[index]->wordCount || i==key_word.size()-1){

            return false;
       }
    }
    currentNode = currentNode->childNodes[index];
}
  currentNode->wordCount++;
  return true;
}

void noPrefix(vector<string> words) {
  Trie *root = new Trie();
for(auto word : words){
  if(!insert_key(root, word)){
      cout<< "BAD SET \n"<< word;
      return;
  }
}
cout<<"GOOD SET ";

}

class Tree:
    def __init__(self, words):
        self.words = words
        self.root = Node(None)
        self.checkForPrefix()
        
        
    def checkForPrefix(self):
        for word in words:
            answer = self.insert(word)

            if answer is not None:
                print("BAD SET")
                print(answer)
                return
    
        print("GOOD SET")
        

    def insert(self, word):
        current = self.root
        
        for i in range(len(word)):
            c = word[i]
            
            if current.branches[self.indexOf(c)] != None and i == len(word) - 1:
                return word
            
            if current.branches[self.indexOf(c)] == None:
                current.branches[self.indexOf(c)] = Node(c)
            
            if current.branches[self.indexOf(c)].isComplete:
                return word
            
            if i == len(word) - 1:
                current.branches[self.indexOf(c)].isComplete = True
                
            current = current.branches[self.indexOf(c)]

        return None

    def indexOf(self, c):
        return ord(c) - 97
        
     
class Node:
    def __init__(self, value):
        self.value = value
        self.isComplete = False
        self.branches = [None] * (ord("j") - ord("a") + 1)    
    


def noPrefix(words):
    # Write your code here
    root = Tree(words)

def noPrefix(words):
    dic = {}
    for i in range(len(words)):
        start = dic
        for j in range(len(words[i])):
            if words[i][j] not in start:
                start[words[i][j]] = {}
            start = start[words[i][j]]
            if '*' in list(start.keys()) or (j == len(words[i]) - 1 and (start)):
                print("BAD SET\n", words[i], sep = '')
                return
        start['*'] = True
    print('GOOD SET')