#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

struct Instance
{
  string name;
  bool selected;

  Instance(const string &name)
  {
    selected=false;
    this->name=name;
  }
};

int main(int argc, char **argv)
{
  if (argc!=2)
  {
    cout << "syntax: selection <file containing the list>\n";
    exit(1);
  }

  ifstream in(argv[1]);
  vector<Instance> list;
  string tmp;
  int nb;

  srandom(2008);

  while(in.good())
  {
    list.clear();

    in >> nb; // number of instances to select;
    getline(in,tmp);

    if (!in.good())
      break;

    while(in.good())
    {
      getline(in,tmp);
      if (tmp.length()==0)
	break;

      list.push_back(Instance(tmp));
    }

    int i,n=0;
    while(n<nb)
    {
      i=random()%list.size();

      if (!list[i].selected)
      {
	list[i].selected=true;
	++n;
      }
    }

    cout << "## " << nb << " instances are selected out of " << list.size() << ":\n";
    for(int i=0;i<list.size();++i)
      if (list[i].selected)
      {
	cout << list[i].name << endl;
      }

    cout << "# done\n\n";
  }
}