#coding: utf-8
#yuki50

from itertools import permutations

n=int(raw_input())
a=map(int,raw_input().split())
m=int(raw_input())
b=map(int,raw_input().split())

a.sort()
b.sort()
b.reverse()

res=m+1
for perm in permutations(a,n):
 temp=b[:]
 i,j=0,0
 while i<n and j<m:
  if temp[j]>=perm[i]:
   temp[j]-=perm[i]
   i+=1
  else:
   j+=1
 res=min(res,j+1)

if res<m+1:
 print res
else:
 print -1