import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.util.HashMap;

class Node {
    public int number;
    public Node parent_node;
}

public class HashSkogen {
    public static void main(String[] args) throws FileNotFoundException, IOException {
        HashMap<Integer, Node> map = new HashMap<Integer, Node>();

        System.out.println("Laeser noder...");
        BufferedReader reader = new BufferedReader(new FileReader("noder.txt"));
        String line;
        while ((line = reader.readLine()) != null) {
            String[] number_strings = line.split(" ");
            int number = Integer.parseInt(number_strings[0]);
            int parent_number = Integer.parseInt(number_strings[1]);
            Node node = new Node();
            node.number = number;
            node.parent_node = map.get(parent_number);
            map.put(number, node);
        }
        System.out.println("Noderna inlaesta.");

        BufferedReader user_reader = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            System.out.println("Ange ett nodnummer: ");
            int node_to_start = Integer.parseInt(user_reader.readLine());
            Node current_node = map.get(node_to_start);
            if (current_node == null) {
                System.out.println("Nod " + node_to_start + " finns inte!");
            }
            else {
                int steps = 0;
                while (current_node.parent_node != null) {
                    ++steps;
                    current_node = current_node.parent_node;
                }
                System.out.println("Rotnod (" + steps + " nivaaer upp): " + current_node.number);
            }
        } // while
    } // main
} // class HittaRoten