n = int(input())
A = list(map(int, input().split()))
m = int(input())
B = list(map(int, input().split()))

B.reverse()
C = [[] for j in range(m)]
for mask in range(1<<n):
    x = 0
    for i in range(n):
        if (mask>>i)&1:
            x += A[i]
    for j in range(m):
        if x <= B[j]:
            C[j].append(mask)
INF =10**18
dp = [INF]*(1<<n)
dp[0] = 0
for j in range(m):
    nx = [INF]*(1<<n)
    for mask1 in range(1<<n):
        nx[mask1] = dp[mask1]
    for mask1 in range(1<<n):
        for mask2 in C[j]:
            nx[mask1|mask2] = min(nx[mask1|mask2], dp[mask1]+1)
    dp = nx
if dp[-1] != INF:
    print(dp[-1])
else:
    print(-1)