import java.util.Spliterators;
import java.util.stream.StreamSupport;

import static java.util.Comparator.comparingInt;
import static java.util.Spliterator.*;
import static java.util.function.Function.identity;
import static java.util.stream.Collectors.toMap;

public class StreamWordCounter {

    public static void main(String[] args) {
        Arrays.stream(args)
              .map(String::toLowerCase)
              .collect(toMap(identity(), Lexeme::new, Lexeme::merge))
              .values()
              .stream()
              .sorted(comparingInt(Lexeme::getCount).thenComparing(Lexeme::getWord))
              .limit(countWords)
              .map(Lexeme::getWord)
              .forEachOrdered(System.out::println);
    }

    private static class Lexeme {
        private final String word;
        private final int count;

        public Lexeme(String word, int count) {
            this.word = word;
            this.count = count;
        }

        public Lexeme(String word) {
            this.word = word;
            this.count = 1;
        }

        public String getWord() {
            return word;
        }

        public int getCount() {
            return count;
        }

        public Lexeme merge(Lexeme other) {
            return new Lexeme(word, count + other.count);
        }
    }
}