n = int(input())
A = list(map(int, input().split()))
m = int(input())
B = list(map(int, input().split()))
A.sort(reverse=True)
B.sort()
ma = B[-1]
C = []
ans = 1 << 30

def ok(C):
    D = C[:]
    D.sort()
    p = 0
    for d in D:
        while p < m and B[p] < d:
            p += 1
        if p == m:
            return False
        p += 1
    return True

def dfs(bit):
    global ans
    if bit == 0:
        if ok(C):
            ans = min(ans, len(C))
        return

    if len(C) >= ans:
        return

    lst = []
    for i in range(n):
        if bit >> i & 1:
            lst.append(i)
    
    a = lst[0]
    le = len(lst) - 1
    for bit2 in range(1 << le):
        tot = A[a]
        dbit = 1 << a
        for j in range(le):
            if bit2 >> j & 1:
                dbit ^= 1 << lst[j + 1]
                tot += A[lst[j + 1]]        
        if tot <= ma:
            C.append(tot)
            dfs(bit ^ dbit)
            C.pop()


dfs((1 << n) - 1)
if ans == 1 << 30:
    ans = -1
print(ans)