#include <bits/stdc++.h>

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define RFOR(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)

#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define pii pair<int, int>
#define vi vector<int>

using namespace std;
template <class S, class T>
ostream& operator<<(ostream& o, const pair<S, T>& p)
{
    return o << "(" << p.first << "," << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& vc)
{
    o << "sz = " << vc.size() << endl
      << "[";
    for (const T& v : vc)
        o << v << ",";
    o << "]";
    return o;
}
using ll = long long;
constexpr ll MOD = 1000000007;

constexpr int MAX = 26;
string a[MAX];
string b[MAX];

bool check[26];
int nextc[26];
int prevc[26];

int main()
{
    int N;
    cin >> N;

    rep(i, 26)
    {
        nextc[i] = -1;
        prevc[i] = -1;
    }

    int length = 0;
    rep(i, N)
    {
        cin >> a[i];
        length += a[i].size();
        rep(j, a[i].size())
        {
            check[a[i][j] - 'A'] = true;
            if (j > 0) {
                prevc[a[i][j] - 'A'] = a[i][j - 1] - 'A';
            }
            if (j < a[i].size() - 1) {
                nextc[a[i][j] - 'A'] = a[i][j + 1] - 'A';
            }
        }
    }
    int M;
    cin >> M;
    rep(i, M)
    {
        cin >> b[i];
        rep(j, b[i].size())
        {
            if (j > 0) {
                prevc[b[i][j] - 'A'] = b[i][j - 1] - 'A';
            }
            if (j < b[i].size() - 1) {
                nextc[b[i][j] - 'A'] = b[i][j + 1] - 'A';
            }
        }
    }

    int s = -1;
    rep(i, 26)
    {
        if (prevc[i] == -1 and check[i]) {
            s = i;
            break;
        }
    }

    int l = 1;
    string str;
    str.push_back(s + 'A');
    while (l < length) {
        if (nextc[s] == -1) {
            break;
        }
        s = nextc[s];
        str.push_back(s + 'A');
        l++;
    }

    if (l == length) {
        cout << str << endl;
    } else {
        cout << -1 << endl;
    }
    return 0;
}