import sys


def input(): return sys.stdin.readline().rstrip()


def main():
    N = int(input())
    *A, = map(int, input().split())
    M = int(input())
    *B, = sorted(map(int, input().split()), reverse=True)

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

    dp = [[None]*(M+1) for i in range(1 << N)]

    def solve(am, b):
        if dp[am][b] is not None:
            return dp[am][b]
        if am == 0:
            return 0
        if b == M:
            return M+1

        ans = M+1
        j = am
        while j > 0:
            if am & (j & -j) != 0 and S[j] <= B[b]:
                ans = min(ans, solve(am-j, b+1)+1)
            j = (j-1) & am

        dp[am][b] = ans
        return ans

    ans = solve((1 << N)-1, 0)
    if ans == M+1:
        ans = -1
    print(ans)


if __name__ == '__main__':
    main()