using System;

public struct KeyValuePair[K,V]
{
  public  mutable  key : K;
  public  mutable  value : V;

  public this(mutable  k : K,mutable  v :  V) { key = k; value = v; }

  public this(mutable  k : K) { key = k; value =Nemerle.Extensions.DefaultValue(V); }
}

public class Collection[T]
{
  public  Item : T;

  public this (mutable  item : T)
  {
    this.Item = item;
  }

  public Find (mutable  item : ref T) :  void
  {
    item = Item;
  }
}

class X
{
  static Main () :  int
  {
    mutable  p =  KeyValuePair (3);
    mutable  q =  KeyValuePair (5, 9);

    mutable  c =  Collection (q);
    c.Find (ref p);

    if (p.key != 5)

    {
       1;

    }

    else
  {
  {
    if (p.value != 9)
    {
       2;
    }
    else
  {
  {

     0;
  }
  }
  }
  }
  }
}

/*
BEGIN-OUTPUT
END-OUTPUT
*/