#include<fstream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
using namespace std;
map<string,bool>eu;
vector<string>es;
string NO0(string s){
	string a;
	for(int i=1;i<s.length();i++)
		a+=s[i];
	return a;
}
class fangchengshi{
public:
	vector<string>from,become;
	void get_fcs(string s){
		int i;
		string u="0";
		for(i=0;i<s.length();i++){
			if(s[i]=='+'){
				from.push_back(u);
				u="0";
			}
			else if(s[i]=='='){
				from.push_back(u);
				u="0";
				goto getbecome;
			}
			else
				u+=s[i];
		}
		getbecome:
		for(i++;i<s.length();i++){
			if(s[i]=='+'){
				become.push_back(u);
				u="0";
			}
			else
				u+=s[i];
		}
		become.push_back(u);
		sort(from.begin(),from.end());
		sort(become.begin(),become.end());
	}
}fcs[403];
bool fcsu[403]={false};
int main(){
	ifstream fi("origin.in");
	ofstream fo("origin.out");
	int n,m;
	string s;
	fi>>n;
	for(int i=0;i<n;i++){
		fi>>s;
		fcs[i].get_fcs(s);
	}
	fi>>m;
	vector<string>ls;
	for(int i=0;i<m;i++){
		fi>>s;
		s="0"+s;
		ls.push_back(s);
		eu[s]=true;
	}
	sort(ls.begin(),ls.end());
	e2:
	for(int i=0;i<n;i++){
		if(!fcsu[i]){
			int j=0,k=0;
			while(j<fcs[i].from.size())
				if(fcs[i].from[j]==ls[k]){
					j++;
					k++;
				}
				else if(ls[k]<fcs[i].from[j])
					k++;
				else
					goto e1;
			j=0;
			for(;j<fcs[i].become.size();j++)
				if(!eu[fcs[i].become[j]]){
					ls.push_back(fcs[i].become[j]);
					es.push_back(NO0(fcs[i].become[j]));
					eu[fcs[i].become[j]]=true;
				}
			sort(ls.begin(),ls.end());
			fcsu[i]=true;
			goto e2;
		}
		e1:;
	}
	sort(es.begin(),es.end());
	fo<<es.size()<<endl;
	for(int i=0;i<es.size();i++)
		fo<<es[i]<<endl;
	return 0;
}