package main

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

func main() {
	log.SetFlags(log.Lshortfile)
	// log.Println("hello")
	sc := newScanner()
	N := sc.nextInt()
	A := make([]string, N)
	for i := 0; i < N; i++ {
		A[i] = sc.nextLine()
	}
	M := sc.nextInt()
	B := make([]string, M)
	for i := 0; i < M; i++ {
		B[i] = sc.nextLine()
	}
	As := make([]string, 0)
	var bfs func(string, int, uint)
	bfs = func(s string, c int, used uint) {
		if c == N {
			As = append(As, s)
			return
		}
		for i := range A {
			u := uint(i)
			// log.Println(used, 1<<u, used&(1<<u))
			if used&(1<<u) == 0 {
				bfs(s+A[i], c+1, used|(1<<u))
			}
		}
	}
	bfs("", 0, 0)
	// log.Println(As)
	// log.Println(B)
	Bs := make([]string, 0)
	var bfs2 func(string, int, uint)
	bfs2 = func(s string, c int, used uint) {
		if c == M {
			Bs = append(Bs, s)
			return
		}
		for i := range B {
			u := uint(i)
			// log.Println(used, 1<<u, used&(1<<u))
			if used&(1<<u) == 0 {
				bfs2(s+B[i], c+1, used|(1<<u))
			}
		}
	}
	bfs2("", 0, 0)
	// log.Println(Bs)
	// log.Println(As)
	// log.Println(Bs)
	var ansString string
	var ansCount int
	for _, a := range As {
		for _, b := range Bs {
			if a == b {
				ansCount++
				ansString = a
			}
		}
	}
	if ansCount == 1 {
		fmt.Println(ansString)
	} else {
		fmt.Println("-1")
	}
	// ans := make([]string, 0)
	// for _, s := range As {
	// 	log.Println(s)
	// 	for {
	// 		hit := false
	// 		var n int
	// 		for i, z := range B {
	// 			l := len(z)
	// 			log.Println(n, l, z)
	// 			log.Println(s[n:n+l], z)
	// 			if s[n:n+l] == z {
	// 				if i == len(B)-1 {
	// 					ans = append(ans, s)
	// 				}
	// 				n += l
	// 				hit = true
	// 			}
	// 		}
	// 		if !hit {
	// 			break
	// 		}
	// 	}
	// }
	// log.Println(ans)
	// if len(ans) == 1 {
	// 	fmt.Println(ans)
	// } else {
	// 	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) 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
		}
	}
}