#include <bits/stdc++.h>
#define rep(i, a) for (int i = (int)0; i < (int)a; ++i)
#define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i)
#define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define popcount __builtin_popcount
using ll = long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 60;

template <class T>
inline bool chmin(T &a, T b)
{
	if (a > b)
	{
		a = b;
		return true;
	}
	return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
	if (a < b)
	{
		a = b;
		return true;
	}
	return false;
}

ll gcd(ll n, ll m)
{
	ll tmp;
	while (m != 0)
	{
		tmp = n % m;
		n = m;
		m = tmp;
	}
	return n;
}

ll lcm(ll n, ll m)
{
	return abs(n) / gcd(n, m) * abs(m); //gl=xy
}

using namespace std;

void solve()
{
	int n;
	cin>>n;
	vector<string>a(n);
	bool ng=false;
	string ans="";
	int cnt=0;
	int sum=0;
	rep(i,n)cin>>a[i],sum+=a[i].size();
	int m;
	cin>>m;
	vector<string>b(m);
	rep(i,m)cin>>b[i];
	rep(i,n){
		string s="",t="";
		s+=a[i];
		while(s.size()<sum||t.size()<sum){
			int pos_a=t.size(),pos_b=s.size();
			//cout<<s<<" "<<t<<"\n";
			bool flag=false;
			if(s.size()>t.size()){
				rep(j,m){
					if(s[pos_a]==b[j][0]){
						t+=b[j];
						flag=true;
						break;
					}
				}
				if(!flag)break;
			}
			else if(s.size()<t.size()){
				rep(j,n){
					if(t[pos_b]==a[j][0]){
						s+=a[j];
						flag=true;
						break;
					}
				}
				if(!flag)break;
			}
			else{//作れたとしても2通り以上作れる
				ng=true;
				break;
			}
		}
		if(s==t){
			++cnt;
			ans=s;
		}
	}
	if(cnt==0||cnt>1){
		ng=true;
	}
	if(ng){
		cout<<-1<<"\n";
	}
	else{
		cout<<ans<<"\n";
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}