def solve(A, B):
    B.sort(reverse=True)
    l = len(A)

    DP = [(100, 100)] * (1 << l)
    DP[0] = (0, 0)

    for i in range(0, (1 << l) - 1):
        u1, u2 = DP[i]
        if u1 == 100:
            return -1
        b = B[u1]
        for j in range(len(A)):
            a = A[j]
            j1 = 1 << j
            if i & j1 == 0:
                if b - u2 > a:
                    n = (u1, u2 + a)
                elif b - u2 == a:
                    n = (u1 + 1, 0)
                else:
                    for k in range(u1 + 1, len(B)):
                        if B[k] > a:
                            n = (k, a)
                            break
                        elif B[k] == a:
                            n = (k + 1, 0)
                            break
                    else:
                        continue
                DP[i | j1] = min(DP[i | j1], n)

    if DP[-1] == (100, 100):
        return -1
    return DP[-1][0] + (1 if DP[-1][1] else 0)


def main():
    N = int(input())
    A = list(map(int, input().split()))
    M = int(input())
    B = list(map(int, input().split()))

    print(solve(A, B))


if __name__ == '__main__':
    main()