import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;


public class sudies {

	/**
	 * @param args
	 * @throws IOException 
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		String line;
		
		BufferedReader inFile = new BufferedReader(new FileReader("studies.in"));
		line = inFile.readLine();
		int round = Integer.valueOf(line);
		double[] gpa = new double[]{4.0,3.7,3.3,3.0,2.7,2.3,2.0,1.7,1.3,1.0};
		
		for (int jjjj = 1; jjjj<=round; jjjj++)
		{
			double[][][] result = new double[11][11][101];
			
			line = inFile.readLine();
			String[] nnnn = line.split(" ");
			int n = Integer.valueOf(nnnn[0]);
			int h = Integer.valueOf(nnnn[1]);
			
			
			int course[][] = new int[n][10];
			for (int i = 0; i<n; i++)
			{
				line = inFile.readLine();
				String[] mn = line.split(" ");
				for (int j = 0; j<10; j++)
					course[i][j] = Integer.valueOf(mn[j]); 
				
			}
			
			for (int i = 0; i<n;i++)
			{
				for (int j = 9; j>=0; j--)
				result[i][1][course[i][j]] = gpa[j];
			}
			
			for (int time= 0; time <=h; time++){
				for (int length = 0; length<=n; length++)
				{
					for (int start = 0; start<n; start++)
					{
						if ((start+length)<=n)
								
						for (int secondlength = 0; secondlength <=n; secondlength++){
							if ((length+secondlength)<=n)
							for (int time2 = 0; time2<h; time2++)
							{
								if ((time+time2)<=h){
								if(result[start][length][time]+result[start+length][secondlength][time2]>result[start][length+secondlength][time+time2])
									result[start][length+secondlength][time+time2] = result[start][length][time]+result[start+length][secondlength][time2];
								}
									
							}
						}
					}
				}
			}
			
			double answer = 0;
			for (int time= 0; time <=h; time++){
				for (int length = 1; length<=n; length++)
				{
					for (int start = 0; start<=n; start++)
						if (result[start][length][time]>answer) {
							answer = result[start][length][time];
						
							
						}
				}
				}
			
 			System.out.println("Data Set "+jjjj+":");
 			System.out.println((new java.text.DecimalFormat("#.##")).format(answer/n));
		
			
		}

	}

}