#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

int main() {
	std::vector<int> next(26, -1);
	std::vector<int> prev(26, -1);
	int n;
	std::cin >> n;
	std::vector<bool> used(26);
	while (n--) {
		std::string s;
		std::cin >> s;
		for (char c : s) {
			used[c - 'A'] = true;
		}
		for (int j = 0; j + 1 < s.size(); j++) {
			next[s[j] - 'A'] = s[j + 1];
			prev[s[j + 1] - 'A'] = s[j];
		}
	}
	int m;
	std::cin >> m;
	while (m--) {
		std::string s;
		std::cin >> s;
		for (char c : s) {
			used[c - 'A'] = true;
		}
		for (int j = 0; j + 1 < s.size(); j++) {
			next[s[j] - 'A'] = s[j + 1];
			prev[s[j + 1] - 'A'] = s[j];
		}
	}

	int c = 0;
	for (int i = 0; i < 26; i++) {
		if (used[i] && prev[i] == -1) {
			c = i + 'A';
		}
	}

	std::string s;
	while (c != -1) {
		s += c;
		c = next[c - 'A'];
	}

	if (s.size() < std::count(used.begin(), used.end(), true)) {
		std::cout << -1 << std::endl;
	} else {
		std::cout << s << std::endl;
	}
}