import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class _10_ExtractAllUniqueWords {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        String input = sc.nextLine().toLowerCase();

        Pattern regex = Pattern.compile("\\w+");
        Matcher matcher = regex.matcher(input);
        Set<String> uniqueWords = new TreeSet<String>();

        while(matcher.find()){
            uniqueWords.add(matcher.group());
        }

        for(String element : uniqueWords){
            System.out.print(element + " ");
        }
    }

}