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


public class SimpleTest {

   public static void main(String[] args) throws IOException {
      DiGraph dg = new DiGraph();
      BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
      String s = "";
      while (true) {
         System.out.println("Enter: \n" + "AN to add node, \n" + "RN to remove node,\n" + "AE to add edge,\n" + "RE to remove edge,\n" + "L to check for loops,\n" + "P to print,\n" + "Q to quit");     
         s = in.readLine();
         if (s.equals("Q")) System.exit(0);
         if (s.equals("P")) dg.print();
         if (s.equals("AN")) {
            System.out.println("Enter the node to add");
            dg.addNode(in.readLine());
         }
         if (s.equals("RN")) {
            System.out.println("Enter the node to remove");
            dg.removeNode(in.readLine());
         }
         if (s.equals("AE")) {
            System.out.println("Enter the source node");
            String source = in.readLine();
            System.out.println("Enter the destination node");
            String dest = in.readLine();
            dg.addEdge(source, dest);
         }
         if (s.equals("RE")) {
            System.out.println("Enter the source node");
            String source = in.readLine();
            System.out.println("Enter the destination node");
            String dest = in.readLine();
            dg.removeEdge(source, dest);
         }
         if (s.equals("L")) {
            System.out.println(dg.loops());
         }
      }
   }
}