package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	sc := NewScanner()
	a := make([]int, 26)
	start := make([]int, 26)

	for i := 0; i < 26; i++ {
		start[i] = -1
		a[i] = -1
	}

	N := sc.NextInt()

	s := make([]string, N)

	length := 0

	for i := 0; i < N; i++ {
		s[i] = sc.NextLine()
		start[s[i][0]-'A'] = i
		for j := 1; j < len(s[i]); j++ {
			a[byte(s[i][j-1]-'A')] = int(s[i][j] - 'A')
			start[s[i][j]-'A'] = -1
		}
		length += len(s[i])
	}

	M := sc.NextInt()
	t := make([]string, M)

	for i := 0; i < M; i++ {
		t[i] = sc.NextLine()
		for j := 1; j < len(t[i]); j++ {
			a[byte(t[i][j-1]-'A')] = int(t[i][j] - 'A')
			start[t[i][j]-'A'] = -1
		}
	}

	for i := 0; i < 26; i++ {
		tmp := ""
		//		used := make([]bool, 26)
		if start[i] >= 0 {
			j := i
			for j >= 0 {
				tmp += string(j + 'A')
				j = a[j]
			}
			if len(tmp) == length {
				fmt.Println(tmp)
				return
			}
		}
	}
	fmt.Println(-1)

}

type Scanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func NewScanner() *Scanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1000)
	return &Scanner{r: rdr}
}
func (s *Scanner) Next() string {
	s.pre()
	start := s.p
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}
	result := string(s.buf[start:s.p])
	s.p++
	return result
}
func (s *Scanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *Scanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}
func (s *Scanner) NextInt64() int64 {
	v, _ := strconv.ParseInt(s.Next(), 10, 64)
	return v
}

func (s *Scanner) NextIntArray() []int {
	s.pre()
	start := s.p
	result := []int{}
	for ; s.p < len(s.buf)+1; s.p++ {
		if s.p == len(s.buf) || s.buf[s.p] == ' ' {
			v, _ := strconv.ParseInt(string(s.buf[start:s.p]), 10, 0)
			result = append(result, int(v))
			start = s.p + 1
		}
	}

	return result
}
func (s *Scanner) NextInt64Array() []int64 {
	s.pre()
	start := s.p
	result := []int64{}
	for ; s.p < len(s.buf)+1; s.p++ {
		if s.p == len(s.buf) || s.buf[s.p] == ' ' {
			v, _ := strconv.ParseInt(string(s.buf[start:s.p]), 10, 64)
			result = append(result, v)
			start = s.p + 1
		}
	}
	return result
}

func (s *Scanner) NextMap() map[int]bool {
	s.pre()
	start := s.p
	mp := map[int]bool{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			mp[v] = true
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	mp[v] = true

	return mp
}

func (s *Scanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *Scanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}