class C1 {
    C2 other;
    C1(C2 other) {
      this.other = other;
    }
  }
  
  class C2 {
    int x;
    C2(int x) {
      this.x = x;
    }
  }
  class Drill2{
    C2 first = new C2(10);
    C2 fourth = new C2(20);
    C1 second = new C1(fourth);
    C1 third = new C1(first);

  }