#include "library.h"

int sumbetween(const int start, const int end)
{ if (start == end)
    return start;
  return start + sumbetween(start+1, end); }

int shortsum(const int N)
{ return N * (N+1) / 2; }

void main()
{ cout << "sumbetween(1,6) = " << sumbetween(1,6) << "\n";
  if (sumbetween(1,10) == shortsum(10))
    cout << "correct for 10\n";
  else
    cout << "incorrect for 10\n";
}