import java.io.*;
import java.util.*;

public class yesorno {
	public static void main(String[] args) {
		try { new yesorno(); }
		catch (Exception e) { e.printStackTrace(); }
	}

	public yesorno() throws Exception {
		BufferedReader br = new BufferedReader(new FileReader(new File("yesorno.in")));
		int dataSets = Integer.parseInt(br.readLine());
		for (int dataSet = 0; dataSet < dataSets; dataSet++) {
			System.out.println("Data Set " + (dataSet + 1) + ":");
			
			//get the l r n line
	        StringTokenizer tok = new StringTokenizer(br.readLine());
	        int min = Integer.parseInt(tok.nextToken());
	        int max = Integer.parseInt(tok.nextToken());
			int n = Integer.parseInt(tok.nextToken());
			
			double question[] = new double[n];
			for (int q = 0; q < n; q++) {
				question[q] = Float.parseFloat(br.readLine());
			
			}
			
			// sorts low to high
			Arrays.sort(question);
			
			int yesUsed = 0;
			int yesRemaining = max;
			double right = 0;
			for (int i = question.length - 1; i >= 0; i--) {
				if(yesUsed < min || (question[i] > 0.5 && yesRemaining > 0)) {
					yesUsed++;
					yesRemaining--;
					right += question[i];
				} else {
					right += 1 - question[i];
				}
			}
			
			System.out.println((new java.text.DecimalFormat("#.##")).format(right));
		}
	}
}