import sys
read=sys.stdin.buffer.read
readline=sys.stdin.buffer.readline
readlines=sys.stdin.buffer.readlines

import itertools
n=int(readline())
a=list(map(int, readline().split()))
m=int(readline())
b=list(map(int, readline().split()))
b.sort(reverse=True)
ok=[[False]*(1<<n) for _ in range(m)]
for i in range(1<<n):
    s=sum(x for j, x in enumerate(a) if i&(1<<j))
    for j, y in enumerate(b):
        if s<=y:
            ok[j][i]=True
dp=[m+1]*(1<<n)
dp[0]=0
for i in range(1<<n):
    k=dp[i]
    if k>=m:
        continue
    mask=(1<<n)-1-i
    j=mask
    while j:
        if ok[k][j]:
            if dp[i^j]>k+1:
                dp[i^j]=k+1
        j=(j-1)&mask
if dp[(1<<n)-1]<=m:
    print(dp[(1<<n)-1])
else:
    print(-1)