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

b.sort(reverse=True)
ans = INF = 100
from itertools import permutations
for lst in permutations(a):
    v = idx = 0
    for ai in lst:
        if v+ai > b[idx]:
            v = ai
            idx += 1
            if idx >= m or b[idx] < ai:
                idx = INF
        else:
            v += ai
        if idx >= ans: break
    ans = min(ans,idx)

print(ans+1 if ans!=INF else -1)