#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <cctype>
#include <algorithm>
#include <cmath>
using namespace std;
//#define USEFREAD
#ifdef USEFREAD
#define InputLen 5000000
char *ptr=(char *)malloc(InputLen);
#define getc() (*(ptr++))
#else
#define getc() (getchar())
#endif
#define SetFile(x) (freopen(#x".in", "r", stdin), freopen(#x".out", "w", stdout))
template<class T>inline void getd(T &x){
	int ch = getc();bool neg = false;
	while(!isdigit(ch) && ch != '-')ch = getc();
	if(ch == '-')ch = getc(), neg = true;
	x = ch - '0';
	while(isdigit(ch = getc()))
		x = x * 10 - '0' + ch;
	if(neg)x = -x;
}
/***********************************************************************/
const int maxn = 402, maxs = 17000;
#include <map>
#include <string>
#include <vector>
#include <queue>
map<string, int> S;
string NAME[maxs];
int Out[maxn][22], p[maxn], q[maxn], N, M, Iter;
vector<int> adj[maxs];
bool old[maxs], tag[maxs], vis[maxn];
inline bool cmp(int a, int b){return NAME[a] < NAME[b];}
#include <iostream>
inline void work(){
	int i, t, ch, id, Acnt = 0;
	char str[15], *it;
	string name;
	getd(N);
	for(i = 0;i < N;++i){
		for(p[i] = 0;;++p[i]){
			it = str;
			while(!isalpha(ch = getc()));
			while(isalpha(ch) || isdigit(ch)){
				*(it++) = ch;
				ch = getchar();
			}
			*it = 0;
			name = string(str);
			if(!S.count(name))S[name] = id = Iter++;
			else id = S[name];
			NAME[id] = name;
			adj[id].push_back(i);
			if(ch == '=')break;
		}
		++p[i];
		for(q[i] = 0;;++q[i]){
			it = str;
			while(!isalpha(ch = getc()));
			while(isalpha(ch) || isdigit(ch)){
				*(it++) = ch;
				ch = getchar();
			}
			*it = 0;
			name = string(str);
			if(!S.count(name))S[name] = id = Iter++;
			else id = S[name];
			NAME[id] = name;
			Out[i][q[i]] = id;
			if(ch != '+')break;
		}
		++q[i];
	}
	queue<int> Q;
	getd(M);
	while(M--){
		cin >> name;
		id = S[name];
		old[id] = tag[id] = true;
		Q.push(id);
	}
	vector<int>::iterator v_it;
	while(!Q.empty()){
		id = Q.front();Q.pop();
		for(v_it = adj[id].begin();v_it != adj[id].end();++v_it){
			if(!(--p[*v_it])){//可以反应
				for(i = 0;i < q[*v_it];++i)if(!tag[t = Out[*v_it][i]]){
					tag[t] = true;
					++Acnt;
					Q.push(t);
				}
			}
		}
	}
	map<string, int>::iterator M_it;
	printf("%d\n", Acnt);
	for(M_it = S.begin();M_it != S.end();++M_it)
		if(tag[(*M_it).second] && !old[(*M_it).second])puts((*M_it).first.c_str());
}

int main(){
	#ifdef DEBUG
	freopen("test.txt", "r", stdin);
	#else       
	SetFile(origin);
	#endif
	#ifdef USEFREAD
	fread(ptr,1,InputLen,stdin);
	#endif
	
	work();
	
#ifdef DEBUG
    printf("\n%.3lf sec \n", (double)clock() / CLOCKS_PER_SEC);
#endif
    return 0;
}