#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
#include <iomanip>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T> T RoundOff(T a){ return int(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }
template<class T, class C> pair<T, C> mp(T a, C b){ return make_pair(a, b); }

const int INF = 1 << 30;
int rec(const int id, map<int, int>& goods, const vector<vint>& table)
{
	int sum = INF;

	if(!table[id].empty())
	{
		sum = 0;
		rep(i, table[id].size())
			sum += rec(table[id][i], goods, table);
	}

	return min(goods[id], sum);
}

int main()
{
	int n;
	while(cin >> n && n)
	{
		map<string, int> namecon;
		map<int, int>    goods;
		vector<vint> d(n, vint(n));

		rep(i, n)
		{
			string name;
			int cost;

			cin >> name >> cost;

			namecon.insert(map<string, int>::value_type(name, i));
			goods.insert(map<int, int>::value_type(i, cost));
		}

		int m;
		cin >> m;
		vector<vint> table(n);

		rep(i, m)
		{
			int num;
			string name;
			cin >> name >> num;

			rep(j, num)
			{
				string mat;
				cin >> mat;
				table[namecon[name]].push_back(namecon[mat]);
			}
		}

		string item;
		cin >> item;

		cout << rec(namecon[item], goods, table) << endl;
	}
}