// Counter.java - a simple wrap around counter
public class Counter {
  //instance variables -fields -- hidden
   private int value;

  // Constructor
  Counter(){value = 0;};

  Counter(int v) throws CounterOutOfRangeException {
    if(v<0 || v>=100)
      throw new CounterOutOfRangeException("Invalid initial value.");
    else
      value = v%100;
  }

  //methods -- exposed
  public void reset() { value = 0; }

  public int get()    { return value;}

  public void click() {value = (value + 1) % 100;}
}