#include <cstdio>
#include <string.h>

using namespace std;

int k, n, m;
double p[26], s;
char word[100][10000];

int main()
{
	freopen("monkeys.in", "r", stdin);
	scanf("%d", &k);
	for (int i = 1; i <= k; i++)
	{
		scanf("%d%d%lf", &n, &m, &s);
		for (int j = 0; j < m; j++)
		{
			char t[2];
			scanf("%s", t);
			scanf("%lf", &p[t[0]-'a']);
		}
		double ans = 0.0;
		for (int j = 0; j < n; j++)
		{
			scanf("%s", word[j]);
			double res = 1.0;
			for (int r = 0; r < strlen(word[j]); r++)
				res *= p[word[j][r]-'a'];
			res *= s;
			ans += res;
		}
		printf("Data Set %d:\n%.4E\n\n", i, ans);
	}
	return 0;
}