import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;

public class _10ExtractAllUniqueWords {

    @SuppressWarnings("resource")
    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);
        List<String> words = new ArrayList<>(
                Arrays.asList(scn.nextLine().toLowerCase().split("\\W+")));

        Set<String> uniqueWords = new TreeSet<>(words);

        uniqueWords.forEach(s -> System.out.print(s + " "));
    }

}