import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;


public class monkeys {

	public static void main(String[] args) throws FileNotFoundException {
		Scanner scanner = new Scanner(new File("monkeys.in"));
		int numDataSets = scanner.nextInt();
		
		for(int i = 0; i < numDataSets; i++) {
			int numWords = scanner.nextInt();
			int numKeys = scanner.nextInt();
			double spaceProbability = scanner.nextDouble();
			
			Map<String, Double> probabilities = new HashMap<String, Double>();
			for(int j = 0; j < numKeys; j++) {
				String key = scanner.next();
				double probability = scanner.nextDouble();
				probabilities.put(key, probability);
			}
			
			List<String> words = new ArrayList<String>();
			for(int k = 0; k < numWords; k++) {
				words.add(scanner.next());
			}

			double totalP = 0.0;
			for(String word:words) {
				char[] chars = word.toCharArray();
				double p = spaceProbability;
				for(char c:chars) {
					p *= probabilities.get(String.valueOf(c));
				}
				totalP += p;
			}
			
			System.out.println("Data Set " + (i+1) + ":");
			System.out.println((new java.text.DecimalFormat("0.####E0")).format(totalP));
			
			if(i != numDataSets-1)
				System.out.println();
		}
	}

}