#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>
#include <fstream>
#include <functional>
#include <chrono>

using namespace std;
#define REP(i, n) for (int (i) = 0; (i) < (n); (i)++)
#define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++)
#define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--)
#define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--)
#define DEBUG(C) cerr << #C << " = " << C << endl;
using LL = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<LL>;
using VVL = vector<VL>;
using VD = vector<double>;
using VVD = vector<VD>;
using PII = pair<int, int>;
using PDD = pair<double, double>;
using PLL = pair<LL, LL>;
using VPII = vector<PII>;
template<typename T> using VT = vector<T>;
#define ALL(a) begin((a)), end((a))
#define RALL(a) rbegin((a)), rend((a))
#define SORT(a) sort(ALL((a)))
#define RSORT(a) sort(RALL((a)))
#define REVERSE(a) reverse(ALL((a)))
#define MP make_pair
#define FORE(a, b) for (auto &&a : (b))
#define FIND(s, e) ((s).find(e) != (s).end())
#define EB emplace_back
template<typename T> inline bool chmax(T &a, T b){if (a < b){a = b;return true;}return false;}
template<typename T> inline bool chmin(T &a, T b){if (a > b){a = b;return true;}return false;}

const int INF = 1e9;
const int MOD = INF + 7;
const LL LLINF = 1e18;
const double EPS = 1e-9;

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

int main() {
    cin >> N;
    A.resize(N);
    REP(i, N) {
        cin >> A[i];
    }
    cin >> M;
    B.resize(M);
    REP(i, M) {
        cin >> B[i];
    }
    if (N == 1) {
        cout << A[0] << endl;
        return 0;
    } else if (M == 1) {
        cout << B[0] << endl;
        return 0;
    }
    // REP(i, N) {
    //     int id = -1;
    //     REP(j, M) {
    //         if (A[i][0] == B[j][0] || A[i][0] == B[j].back()) {
    //             id = j; break;
    //         }
    //     }
    //     if (id != -1) {
    //         REP(j, M) {
    //             if (id != j && A[i].back() == B[j][0] || A[i].back() == B[j].back()) {
    //                 cout << -1 << endl;
    //                 return 0;
    //             }
    //         }
    //     }
    // }
    while (A.size() > 1) {
        VT<string> new_A;
        VT<bool> used(A.size(), false);
        REP(i, A.size()) {
            if (!used[i]) {
                REP(j, A.size()) {
                    if (!used[j]) {
                        REP(k, B.size()) {
                            REP(l, (int) B[k].size() - 1) {
                                if (A[i].back() == B[k][l] && A[j].front() == B[k][l + 1]) {
                                    used[i] = used[j] = true;
                                    new_A.EB(A[i] + A[j]);
                                    goto next;
                                }
                            }
                        }
                    }
                }
            }
            next:;
        }
        if (new_A.empty()) {
            cout << -1 << endl;
            return 0;
        }
        A = new_A;
    }
    cout << A.front() << endl;
}