import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
        String[] strs = {"eat", "tea", "tan", "ate", "nat", "bat"};
        Map<String, List<String>> mapang = new HashMap<>();
        for (String s : strs){
            char[] ch = s.toCharArray();
            Arrays.sort(ch);
            String key = String.valueOf(ch);
            if(!mapang.containsKey(key)){
                mapang.put(key, new ArrayList<>());
            }
            mapang.get(key).add(s);
        }
        List<List<String>> anglist = new ArrayList<>();
        for(Map.Entry<String, List<String>> entry: mapang.entrySet()){
            anglist.add(entry.getValue());
        }
        System.out.println(anglist);
    }
}