import times, strutils, sequtils, math, algorithm, tables, sets, lists, intsets
import critbits, future, strformat, deques
template `max=`(x,y) = x = max(x,y)
template `min=`(x,y) = x = min(x,y)
template `mod=`(x,y) = x = x mod y
template scan2 = (scan(), scan())
template scan3 = (scan(), scan())
let read* = iterator: string {.closure.} =
    while true: (for s in stdin.readLine.split: yield s)
proc scan(): int = read().parseInt
proc scanf(): float = read().parseFloat
proc toInt(c:char): int =
    return int(c) - int('0')



proc solve()=
  var
    n = scan()
    clue1 = newseqwith(n,read())
    m = scan()
    clue2 = newseqwith(m,read())
    es = newseqwith(26,newseq[int]())
    ies = newseqwith(26,newseq[int]())
    app = newseqwith(26,false)
  for clue in clue1 & clue2:
    for c in clue:
      app[c.ord-'A'.ord]=true
    for i in 0..<clue.len-1:
      if clue[i+1].ord-'A'.ord notin es[clue[i].ord-'A'.ord]:
        es[clue[i].ord-'A'.ord].add(clue[i+1].ord-'A'.ord)
        ies[clue[i+1].ord-'A'.ord].add(clue[i].ord-'A'.ord)
  #echo es.join("\n")
  var s = -1
  for idx, v in app:
    if v:
      s = idx
      break
  var
    v = s
    touch = newseqwith(26,false)
  while ies[v].len>0:
    v = ies[v][0]
    # ループがあったら不可能
    if touch[v]:
      echo -1
      return
    touch[v]=true
  # ループがなければ始点についている
  touch.fill(false)
  var res = newseq[char]()
  res.add((v+'A'.ord).chr)
  touch[v]=true
  while es[v].len>0:
    if es[v].len>1:
      echo -1
      return
    v = es[v][0]
    touch[v]=true
    res.add((v+'A'.ord).chr)
  for i in 0..<26:
    if app[i] and not touch[i]:
      echo -1
      return
  echo res.join("")


      

  

  
solve()