#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <deque>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <bitset>
#include <functional>
#include <utility>
#include <algorithm>
#include <numeric>
#include <typeinfo>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <ctime>

using namespace std;

#define dump(n) cout<<"# "<<#n<<"="<<(n)<<endl
#define debug(n) cout<<__FILE__<<","<<__LINE__<<": #"<<#n<<"="<<(n)<<endl
#define repi(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,n) repi(i,0,n)
#define iter(c) __typeof((c).begin())
#define foreach(i,c) for(iter(c) i=(c).begin();i!=(c).end();i++)
#define allof(c) (c).begin(),(c).end()
#define mp make_pair

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int,int> pii;

int solve(string& name,map<string,int>& prices,map<string,vs>& needs)
{
	if(needs.count(name)==0)
		return prices[name];
	int res=0;
	foreach(i,needs[name])
		res+=solve(*i,prices,needs);
	return min(prices[name],res);
}

int main()
{
	for(int n;cin>>n,n;){
		map<string,int> prices;
		rep(i,n){
			string name;
			int price;
			cin>>name>>price;
			prices[name]=price;
		}
		map<string,vs> needs;
		int m;
		cin>>m;
		rep(i,m){
			string name;
			int k;
			cin>>name>>k;
			rep(j,k){
				string elem;
				cin>>elem;
				needs[name].push_back(elem);
			}
		}
		
		string name;
		cin>>name;
		cout<<solve(name,prices,needs)<<endl;
	}
	
	return 0;
}