import sequtils,strutils,strscans,algorithm,math,future,macros
template get*():string = stdin.readLine() #.strip()
template `max=`*(x,y:typed):void = x = max(x,y)
template optPow{`^`(2,n)}(n:int) : int = 1 shl n
template If*(ex:untyped):untyped = (if not(ex) : continue)
import times

let
  N = get().parseInt()
  A = get().split().map(parseInt).sorted(cmp,Descending) # toy <20
  M = get().parseInt()
  B = get().split().map(parseInt).sorted(cmp,Descending) # box <20

var state = newSeqWith(2^N,0)
for n in 0 ..< 2^N:
  for ia in 0 ..< N:
    If: (n and 2^ia) == 2^ia
    state[n] += A[ia] # 各状態の体積の和

var ans = state.mapIt(B[0] - it >= 0)
if ans[2^N - 1] :
  echo 1
  quit()
for i,b in B[1..^1]:
  var n_ans = state.mapIt(false)
  for x,a in ans:
    If: a
    for y,s in state:
      If: (x and y) == 0
      If: b - s >= 0
      n_ans[x xor y] = true
  ans = n_ans
  if ans[2^N - 1] :
    echo i+2
    quit()
echo -1