#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define rep(i,n) for(int i=0;i<(n);i++)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define ALL(x) (x).begin(), (x).end()
constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1;
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
template<class T>inline int popcount(T a) {return __builtin_popcount(a);}
template<class T>inline T emod(T a, T p) { return (a%p + p) % p;}
//-------------------
int main() {
    cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(15);
    int n; cin >> n;
    unordered_map<char, char> mp;
    unordered_map<char, int> usi;
    rep(i,n) {
        string s; cin >> s;
        for(int i=0; i<s.size(); i++) {
            if(i==s.size()-1) mp[s[i]] = '-';
            else mp[s[i]] = s[i+1];
            usi[s[i]];
            if(i!=0) usi[s[i]]++;
        }
    }
    int m; cin >> m;
    rep(i,m) {
        string s; cin >> s;
        for(int i=0; i<s.size(); i++) {
            usi[s[i]];
            if(i!=0) usi[s[i]]++;
            if(mp[s[i]]!='-') continue;
            if(i==s.size()-1) mp[s[i]] = '-';
            else mp[s[i]] = s[i+1];
        }
    }
    int cnt = 0;
    for(auto [k,v]: mp) {
        // cout << k << " " << v << endl;
        cnt += v=='-'? 1:0;
    }
    if(cnt > 1) cout << -1 << endl;
    else {
        char cur;
        for(auto [k,v]: usi) {
            // cout << k << " " << v << endl;
            if(v==0) cur = k;
        }
        // cout << cur << endl;
        while(true) {
            if(cur == '-') break;
            cout << cur;
            cur = mp[cur];
        }
        cout << endl;
    }
    return 0;
}