#include "main.h"
#include "pointset.h"

main()
{
  int numpoints, numfaces;

  cin >> numfaces;

  cin >> numpoints;
  pointset avgface(numpoints);

  avgface.read_points();

  for (int i = 0; i < numfaces-1; ++i)
  {
    cin >> numpoints;
    pointset tmp(numpoints);
    tmp.read_points();
    avgface.add(tmp);
  }
  
  avgface.scale(1.0/numfaces);		// divide by N to get the average
  avgface.prn_points();
}