import heapq
N = int(input())
A = [int(x) for x in input().split()]
B = [int(x) for x in input().split()]
H = [(A[i],0) for i in range(N)]
heapq.heapify(H)
min_max_cnt = N
for i in range(N):
    h = H[:]
    for j in range(N):
        t = heapq.heappop(h)
        cnt = t[1]+1
        heapq.heappush(h, (B[j-i]//2+t[0], cnt))
    min_max_cnt = min(min_max_cnt, max(t[1] for t in h))
print(min_max_cnt)