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

class MSortApp {

  private static Scanner keyboardInput = new Scanner (System.in);
  private static MSort s = new MSort();
  private static final int INPUT = 0;
  private static final int PRINTALL = 1;
  private static final int MSORT = 2;
  private static final int EXIT = -1;

  // main program
  public static void main(String[] args) throws Exception {

    int choice;
    s.input();
    while ((choice = displayMenu()) != -1) {
      choiceAction(choice);
    }
  }

  
  // display Menu and get choice
  private static int displayMenu() {
    int tmp = 0;
    try {
      System.out.println();
      System.out.println("   " + INPUT + " Input numbers again");
      System.out.println("   " + PRINTALL + " Print all numbers");
      System.out.println("   " + MSORT + " Merge sort ascendingly");
      System.out.println("   " + EXIT + " Exit");
      System.out.print("   Choose one of the above options: ");
      tmp = keyboardInput.nextInt();
    }
    catch (Exception e) {
      keyboardInput.next();
    }
    return(tmp);
  }

  private static void choiceAction(int choice) {
    switch(choice) {
      case INPUT: 
        s.input();
        break;
      case MSORT: 
        s.msort();
        break;
      case PRINTALL: 
        s.printAll();
        break;
      default: 
        System.out.println("Incorrect option!");
        break;
    }
  }
  
}