N = int(input())
A = list(map(int, input().split()))
M = int(input())
B = list(map(int, input().split()))
B.sort(reverse=True)

inf = 10 ** 18
ans = inf

def dfs(L = [], now = 0):
    global ans
    if len(L) > len(B) or len(L) >= ans:
        return
    if now == N:
        temp = []
        for a in L:
            temp.append(a)
        temp.sort(reverse=True)
        for i in range(len(temp)):
            if temp[i] > B[i]:
                return
        ans = min(ans, len(temp))     
        return
    for i in range(len(L)):
        L[i] += A[now]
        dfs(L, now + 1)
        L[i] -= A[now]
    L.append(A[now])
    dfs(L, now + 1)
    L.pop()
    return 

dfs()
print(ans) if ans != inf else print(-1)