using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

class Program
{
    public void Proc()
    {

        List<string> ac1 = new List<string>();
        int cnt = int.Parse(Reader.ReadLine());
        for (int i = 0; i < cnt; i++)
        {
            ac1.Add(Reader.ReadLine());
        }

        List<string> ac2 = new List<string>();

        cnt = int.Parse(Reader.ReadLine());
        for (int i = 0; i < cnt; i++)
        {
            ac2.Add(Reader.ReadLine());
        }

        string ans = this.GetAns(ac1, ac2);
        Console.WriteLine(ans);
        

    }


    private string GetAns(List<string> ac1, List<string> ac2)
    {
        if (ac1.Count == 1)
        {
            return ac1[0];
        }
        if (ac2.Count == 1)
        {
            return ac2[0];
        }

        if(ac1.Count <= 0 || ac2.Count <= 0) {
            return "-1";
        }

        for (int i = 0; i < ac1.Count; i++)
        {
            char target = ac1[i].First();
            string tmp = ac2.Where(a => a.Contains(target)).First();
            int idx = tmp.IndexOf(target);
            if (idx > 0)
            {
                char prevChar = tmp[idx - 1];
                int idxPrev = ac1.IndexOf(ac1.Find(a => a.Last() == prevChar));
                return GetAns(Join(ac1, idxPrev, i), ac2);
            }

            target = ac1[i].Last();
            tmp = ac2.Where(a => a.Contains(target)).First();
            idx = tmp.IndexOf(target);
            if (tmp.Last() != target)
            {
                char nextChar = tmp[idx + 1];
                int idxNext = ac1.IndexOf(ac1.Find(a => a.First() == nextChar));
                return GetAns(Join(ac1, i, idxNext), ac2);
            }
        }

        for (int i = 0; i < ac2.Count; i++)
        {
            char target = ac2[i].First();
            string tmp = ac1.Where(a => a.Contains(target)).First();
            int idx = tmp.IndexOf(target);
            if (idx > 0)
            {
                char prevChar = tmp[idx - 1];
                int idxPrev = ac2.IndexOf(ac2.Find(a => a.Last() == prevChar));
                return GetAns(ac1, Join(ac2, idxPrev, i));
            }

            target = ac2[i].Last();
            tmp = ac1.Where(a => a.Contains(target)).First();
            idx = tmp.IndexOf(target);
            if (tmp.Last() != target)
            {
                char nextChar = tmp[idx + 1];
                int idxNext = ac2.IndexOf(ac2.Find(a => a.First() == nextChar));
                return GetAns(ac1, Join(ac2, i, idxNext));
            }
        }

        return "-1";

    }


    private List<string> Join(List<string> list, int idx1, int idx2)
    {
        List<string> ret = new List<string>();
        ret.AddRange(list);
        ret.RemoveAt(Math.Max(idx1, idx2));
        ret.RemoveAt(Math.Min(idx1, idx2));
        ret.Add(list[idx1] + list[idx2]);
        return ret;

    }







    public class Reader
    {
        public static bool IsDebug = false;
        private static String PlainInput = @"





2
EA
T
2
T
EA





";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
    }
    static void Main()
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}