//prints 5 0 6 6

class C extends Object {
  var nat n;
  C identity(C unused) {this;}
  nat getN(C unused) {this.n;}
}

main {
  var C c;
  printNat(  (new C).n=5 );  
  c = (new C).identity(c).identity(c).identity(c);
  printNat(c.n);  
  c.identity(c).identity(null).identity(c).identity(null).n = 6;
  printNat(c.n); 
  printNat(c.identity(c).getN(c));
}