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()))
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=[False]*(1<<(n+m))
dp[0]=True
for i in range(1<<(n+m)):
    j0=m
    for j in range(m):
        if i&(1<<j):
            j0=j
            break
    else:
        continue
    mask=i&(((1<<n)-1)<<m)
    k=mask
    while k:
        if ok[j0][k>>m] and dp[i^k^(1<<j0)]:
            dp[i]=True
            break
        k=(k-1)&mask
def popcount(x):
    return bin(x).count('1')
ans=[popcount(i) for i in range(1<<m) if dp[(((1<<n)-1)<<m)^i]]
if ans:
    print(min(ans))
else:
    print(-1)