#include <iostream.h>
#include <stl.h>

int main ()
{
  set<int, less<int> > s;
  cout << "count (42) = " << s.count (42) << endl;
  s.insert (42);
  cout << "count (42) = " << s.count (42) << endl;
  s.insert (42);
  cout << "count (42) = " << s.count (42) << endl;
  int count = s.erase (42);
  cout << count << " elements erased" << endl;
  return 0;
}