class RationalNumber {
  // Data fields for numerator and denominator
  private int numerator;
  private int denominator;

  /** Default constructor */
  public RationalNumber() {
    this.numerator = 0;
	  this.denominator = 1;
  }

  /** Construct a rational with specified numerator and denominator */
  public RationalNumber(int numerator, int denominator) throws IrrationalNumberException{
    if (denominator == 0)
    {
	  throw new IrrationalNumberException("Denominator cannot be 0. ",numerator, denominator);
    }
	  
    this.numerator = numerator;
    this.denominator = denominator;
  }

  /** Return numerator */
  public int getNumerator() {
    return numerator;
  }

  /** Return denominator */
  public int getDenominator() {
    return denominator;
  }

  /** Add a rational number to this rational */
  public RationalNumber add(RationalNumber secondRational) {
    
	RationalNumber rn = null;
    int n = numerator*secondRational.getDenominator() +
    denominator*secondRational.getNumerator();
    int d = denominator*secondRational.getDenominator();
    
    try{
    	rn = new RationalNumber(n,d);
    }
    catch(IrrationalNumberException ine){
    	System.out.println(ine.getMessage());
    }
    
    return rn;
  }

  /** Subtract a rational number from this rational */
  public RationalNumber subtract(RationalNumber secondRational) {
	RationalNumber rn = null;
    int n = numerator*secondRational.getDenominator()
      - denominator*secondRational.getNumerator();
    int d = denominator*secondRational.getDenominator();
    try{
    	rn = new RationalNumber(n,d);
    }
    catch(IrrationalNumberException ine){
    	System.out.println(ine.getMessage());
    }
    
    return rn;
  }

  /** Multiply a rational number to this rational */
  public RationalNumber multiply(RationalNumber secondRational) {
	RationalNumber rn = null;
    int n = numerator*secondRational.getNumerator();
    int d = denominator*secondRational.getDenominator();
    try{
    	rn = new RationalNumber(n,d);
    }
    catch(IrrationalNumberException ine){
    	System.out.println(ine.getMessage());
    }
    
    return rn;

  }

  /** Divide a rational number from this rational */
  public RationalNumber divide(RationalNumber secondRational) throws IrrationalNumberException{
    if (secondRational.getNumerator() == 0)
    {
	  throw new IrrationalNumberException("Trying to divide by 0. ",secondRational.numerator, secondRational.denominator);
    }

    int n = numerator*secondRational.getDenominator();
    int d = denominator*secondRational.getNumerator();
    return new RationalNumber(n, d);
  }
  
  /** Override the toString() method */
  public String toString() {
    if (denominator == 1)
      return numerator + "";
    else
      return numerator + "/" + denominator;
  }
}


class IrrationalNumberException extends Exception {
  public int numerator;
  public int denominator;

  public IrrationalNumberException(String message, int numerator, int denominator) {
    super(message);
    this.numerator = numerator;
    this.denominator = denominator;
  }
  public String getMessage() {
    return super.getMessage() + "\n" + "numerator = "+ numerator + " and denominator = " + denominator;
  }
}



class Driver {
  public static void main(String args[]) {
    System.out.println("The result is " + performDivide());
  }

  public static RationalNumber performDivide() {
    RationalNumber r1 = null, r2 = null, r3 = null;

    while(r3 == null) {
      try {
        System.out.println("Enter the first numerator, then first denominator...");
        r1 = new RationalNumber(UserInput.readInt(), UserInput.readInt());
        System.out.println("Enter the second numerator, then second denominator...");
        r2 = new RationalNumber(UserInput.readInt(), UserInput.readInt());
        r3 = r1.divide(r2);
        System.out.println(r3.toString());
      }
      catch(IrrationalNumberException e) {
        System.out.println(e.getMessage());
        System.out.println("Exit (e)");
        System.out.println("Return (r)");
        System.out.println("Try Again (t)");
        System.out.print("\nChoice?  ");
        char choice = UserInput.readChar();
        if (choice == 'e') {
          System.out.println("Exiting...");
          System.exit(0);
        }
        else if (choice == 'r') {
          System.out.println("Returning...");
          try{
        	  r1 = new RationalNumber(0,1);
          }
          catch(IrrationalNumberException ine){
        	  System.out.println(ine.getMessage() + "\n" + r3.toString());
          }
          return r1;
        }
      }
      finally {
        System.out.println("Finally is executed in any case!");
      }
    }
    return r3;
  }
}