#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
 
using namespace std;
 
#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define clr(a, b) memset((a), (b) ,sizeof(a))
 
#define MOD 1000000007

int main(){
  int c = 0;
  int n;
  cin>>n;
  vector<string> v;
  rep(i,0,n){
    string s;
    cin>>s;
    v.pb(s);
    c+=s.sz;
  }
  int m;
  cin>>m;
  rep(i,0,m){
    string s;
    cin>>s;
    v.pb(s);
  }
  rep(i,0,v.sz){
    string s1 = string(200,'?');
    rep(j,0,v[i].sz){
      s1[j]=v[i][j];
    }
    rep(j,0,v.sz){
      rep(k,0,v.sz){
        rep(l,0,100){
          if(s1[l]=='?')break;
          int flag = 1;
          rep(m,0,v[k].sz){
            if(s1[l+m]=='?')continue;
            if(s1[l+m]!=v[k][m])flag = 0;
          }
          if(flag==1){
            rep(m,0,v[k].sz){
              s1[l+m]=v[k][m];
            }
          }
        }
      }
    }
    string ans;
    rep(j,0,s1.sz){
      if(s1[j]=='?')break;
      ans += s1[j];
    }
    if(ans.sz==c){
      cout << ans << endl;
      return 0;
    }
  }
  cout << "-1" << endl;
  return 0;
}