class consCell {
private:
  int data;
  consCell *next;
public:

  consCell(int d): data(d),next(NULL) {}
  consCell(int d, consCell* n) : data(d),next(n) {}
  consCell(const consCell& c) { next = c.next; data = c.data; } // coppyu constructor

  consCell* cdr() {return next;}
  int car() {return data;}
};