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

int N, M;
std::vector<std::string> A, B;

int main()
{
    int chain;
    std::cin >> N;
    A.resize(N);
    for (int i = 0; i < N; i++)
    {
        std::cin >> A[i];
    }
    std::cin >> M;
    B.resize(M);
    for (int i = 0; i < M; i++)
    {
        std::cin >> B[i];
    }
    if (N == 1)
    {
        std::cout << A[0] << std::endl;
        return 0;
    }
    else if (M == 1)
    {
        std::cout << B[0] << std::endl;
        return 0;
    }
    chain = N - 1;
    while (chain > 0)
    {
        int old_chain = chain;
        for (int i = 0; i < A.size(); i++)
        {
            for (int j = i + 1; j < A.size(); j++)
            {
                if (A[i] == "")
                {
                    continue;
                }
                std::string tmp1, tmp2;
                tmp1 = std::string() + A[i].back() + A[j].front();
                tmp2 = std::string() + A[j].back() + A[i].front();
                for (int k = 0; k < M; k++)
                {
                    if (B[k].find(tmp1) != std::string::npos)
                    {
                        A[i] += A[j];
                        A[j] = "";
                        chain--;
                        break;
                    }
                    if (B[k].find(tmp2) != std::string::npos)
                    {
                        A[j] += A[i];
                        A[i] = "";
                        chain--;
                        break;
                    }
                }
            }
        }
        if (chain == old_chain)
        {
            std::cout << -1 << std::endl;
            return 0;
        }
    }
    for (int i = 0; i < N; i++) {
        if (A[i] != "") {
            std::cout << A[i] << std::endl;
            break;
        }
    }
}