#include <algorithm>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <vector>

using namespace std;

#define reps(i,f,n) for(int i=f; i<int(n); ++i)
#define rep(i,n) reps(i,0,n)

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;

const int INF = 1001001001;

int n;
int price[100];
vi recipe[100];
int memo[100];
int search(int id)
{
	if(memo[id] >= 0)
		return memo[id];
	if(memo[id] == -2)
		return price[id];
	if(recipe[id].empty())
		return memo[id] = price[id];
	
	memo[id] = -2;
	int sum = 0;
	rep(i, recipe[id].size()){
		sum += search(recipe[id][i]);
	}
	return memo[id] = min(price[id], sum);
}

int main()
{
	int n;
	while(scanf("%d", &n), n){
		fill(memo, memo+n, -1);
		rep(i, n)
			recipe[i].clear();
		
		map<string, int> dict;
		rep(i, n){
			char tmp[128];
			scanf("%s%d", tmp, &price[i]);
			dict[tmp] = i;
		}
		
		int m;
		scanf("%d", &m);
		rep(i, m){
			char tmp[128];
			scanf("%s", tmp);
			int id = dict[tmp];
			int k;
			scanf("%d", &k);
			rep(j, k){
				scanf("%s", tmp);
				recipe[id].push_back(dict[tmp]);
			}
		}
		
		char tmp[128];
		scanf("%s", tmp);
		printf("%d\n", search(dict[tmp]));
	}
	return 0;
}