#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
map<string,int> data;
map<string,vector<string> >ren;

int res(string s){
	if(!ren.count(s))return data[s];
	int sum = 0;
	for(int i =0;i <ren[s].size();i++){
		sum +=res(ren[s][i]);
	}
	if(data[s]>sum){
		data[s]=sum;
	}
	return data[s];
}

int main(){
	int n,m;
	while(cin>>n,n){
		data.clear();
		ren.clear();
		for(int i =0;i < n;i++){
			string item;
			int cst;
			cin>>item>>cst;
			data[item] =cst;
		}
		cin>>m;
		int k;
		for(int i =0;i <m;i++){
			string renkin;
			cin>>renkin>>k;
			//int sum=0;
			for(int j =0;j <k;j++){
				string tmp;
				cin>>tmp;
				ren[renkin].push_back(tmp);
			}
			//data[renkin]=min(sum,data[renkin]);
		}
		string ans;
		cin>>ans;
		cout <<res(ans)<<endl;
	}
	return 0;
}