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

public class Friends1 {
    public static void main(String[] args) throws FileNotFoundException {
        System.out.println("Welcome to the cse143 friend finder.");
        Scanner input = new Scanner(new File("friends.dot"));
        Map<String, Set<String>> friends = readFile(input);
        System.out.println(friends);

        // more to do
    }

    public static Map<String, Set<String>> readFile(Scanner input) {
        Map<String, Set<String>> friends = new TreeMap<>();
        while (input.hasNextLine()) {
            String line = input.nextLine();
            if (line.contains("--")) {
                Scanner lineData = new Scanner(line);
                String name1 = lineData.next();
                lineData.next();  // this skips the "--" token
                String name2 = lineData.next();
                addTo(friends, name1, name2);
                addTo(friends, name2, name1);
            }
        }
        return friends;
    }

    public static void addTo(Map<String, Set<String>> friends, String name1, 
                             String name2) {
        if (!friends.containsKey(name1)) {
            Set<String> theFriends = new TreeSet<>();
            friends.put(name1, theFriends);
            theFriends.add(name2);
        } else {
            Set<String> theFriends = friends.get(name1);
            theFriends.add(name2);
        }
    }
}