#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "math.h"
#include "utility"
#include "string"
#include "map"
#include "unordered_map"
#include "iomanip"
#include "random"

using namespace std;
const long long int MOD = 1000000007;
list<long long int> Prime(int M) {
	list<long long int>P;
	P.push_back(2);
	P.push_back(3);
	for (int i = 5; i <= M; i += 6) {
		bool flag = true;
		for (auto j : P) {
			if (i%j == 0) {
				flag = false;
				break;
			}
		}
		if (flag)P.push_back(i);
		flag = true;
		for (auto j : P) {
			if ((i + 2) % j == 0) {
				flag = false;
				break;
			}
		}
		if (flag)P.push_back(i + 2);
	}
	return P;
}

long long int N, M, K, Q;
long long int ans;

int nx[26];
int bf[26];
bool flag[26];
string s;
string ret;
int box;

int main() {
	ios::sync_with_stdio(false);
	for (int i = 0; i < 26; i++) {
		nx[i] = -1;
		bf[i] = -1;
	}
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> s;
		for (int j = 0; j < s.size(); j++) {
			flag[s[j] - 'A'] = true;
			if (j) {
				bf[s[j] - 'A'] = s[j - 1] - 'A';
				nx[s[j - 1] - 'A'] = s[j] - 'A';
			}
		}
	}
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> s;
		for (int j = 0; j < s.size(); j++) {
			flag[s[j] - 'A'] = true;
			if (j) {
				bf[s[j] - 'A'] = s[j - 1] - 'A';
				nx[s[j - 1] - 'A'] = s[j] - 'A';
			}
		}
	}
	for (int i = 0; i < 26; i++) {
		if (flag[i] && bf[i] == -1) {
			box = i;
			ans++;
		}
	}
	if (ans > 1) {
		cout << "-1\n";
		return 0;
	}
	while (nx[box] != -1) {
		cout << char('A' + box);
		box = nx[box];
	}
	for (int i = 0; i < 26; i++) {
		if (flag[i] && nx[i] == -1) {
			cout << char('A' + i);
		}
	}
	cout << endl;
	return 0;
}