N=int(input())
A=list(map(int,input().split()))
M=int(input())
B=list(map(int,input().split()))
B.sort(reverse=True)
dp=[False]*(1<<N)
dp[0]=True
ans=0
for b in B:
    for bit in range((1<<N)-1,-1,-1):
        bit_=bit
        while bit_:
            if sum(A[i] for i in range(N) if bit_&1<<i)<=b:
                dp[bit]|=dp[bit^bit_]
            bit_-=1
            bit_&=bit
    ans+=1
    if dp[-1]:
        break
else:
    ans=-1
print(ans)