N = int(input())
A = list(map(int, input().split(' ')))
M = int(input())
B = list(map(int, input().split(' ')))

sum = [0 for _ in range(1<<N)]
for i in range(1<<N):
    for j in range(N):
        if i & (1<<j):
            sum[i] = sum[i] + A[j]

# dp[i][j]: minimum number of boxes
# when boxes are used until i to accommodate j collection of toys
dp = []
for i in range(M+1):
    dp.append([float('inf') for _ in range(1<<N)])

dp[0][0] = 0

for i in range(M):
    for j in range(1<<N):
        if dp[i][j] == float('inf'):
            continue
        for k in range(1<<N):
            if (j & k == 0) and (sum[k] <= B[i]):     
                dp[i+1][j|k] = min(dp[i+1][j|k], dp[i][j]+1)

answer = float('inf')
for i in range(M+1):
    answer = min(answer, dp[i][(1<<N)-1])

if answer != float('inf'):
    print(answer)
else:
    print(-1)