gistfile1.txt

// the solution 

// 1. declare the class Number(Int)
// 2. define method Number.inc(): Number
// 3. define method Number.dec(): Number
// 4. define getNumber():Int

class Number(val n : Int) { // n cannot be changed!

  def inc(): Number = new Number(n + 1)
  def dec(): Number = new Number(n - 1)
  def getNumber() : Int = n
}