1struct R
2{
3  long long r1, r2;
4  void copy (R const &r) { r1 = r.r1; r2 = r.r2; }
5  R ();
6  explicit R (int, int);
7  R (R const &r) { copy (r); }
8  static int compare (R const &, R const &);
9};
10