#include <fstream.h>

int main(int argc, char* argv[])
{
	int K = 0;
	int N = 0;

	double n[200][2] = {0};

	int c[400];

	int i,j,k,l,m;

	int slices;
	int maxslices = 1;
	int temp;

	int final;

	double pi = 3.141592654;
	double ssize = 0;
	double start;


	ifstream infile("probe.in");
	ofstream outfile("probe.out");

	infile >> K;
	infile.getline((char*)NULL, 100);

	for (i = 0; i < K; i++)
	{
		outfile << "Data Set " << i+1 << ": ";

		maxslices = 1;

		infile >> N;
		infile.getline((char*)NULL, 100);

		for (j = 0; j < 400; j++)
		{
			c[j] = 0;
		}


		for (j = 0; j < 200; j++)
		{
			c[j] = 0;
			n[j][0] = 0;
			n[j][1] = 0;
		}

		for (j = 0; j < N; j++)
		{
			infile >> n[j][0];
			infile >> n[j][1];

			n[j][0] += 2*pi;

		}


		for (slices = 2; slices < 200; slices++)
		{
			ssize = (2*pi) / slices;

			for (int k = 0; k < N; k++)
			{
				start = n[k][0];

				for (int l = 0; l < slices; l++)
					c[l] = 0;
			
				for (int m = 0; m < N; m++)
				{


					for (l = 0; l < slices; l++)
					{
						if (n[m][0]-start >= 0)
						{

							if (n[m][0]-start >= l*ssize && n[m][0]-start < (l+1)*ssize)
								c[l]++;
						}
						else
						{
							if (n[m][0]-start+ (2*pi) >= l*ssize && n[m][0]-start+ (2*pi) < (l+1)*ssize)
								c[l]++;

						}
					}
				}

				final = 1;

				temp = c[0];
				for (l = 1; l < slices; l++)
					if (temp != c[l])
						final = 0;


				if (final == 1)
				{/*
					for (m = 0; m < slices; m++)
						cout << c[m] << "\n";*/

					maxslices = slices;
				}


			}
		}

		outfile << maxslices << " slices\n\n";


	}

	infile.close();
	outfile.close();

	return 0;
}