import heapq
from types import LambdaType

n = int(input())

allies = list(map(int, input().split()))
enemies = list(map(lambda x: int(x) // 2, input().split()))

ans = n + 1

for s in range(n):
    que = [(allies[i], 0) for i in range(n)]
    heapq.heapify(que)
    temp = 0
    for j in range(n):
        u = heapq.heappop(que)
        heapq.heappush(que, (u[0] + enemies[(s + j) % n], u[1] + 1))
        temp = max(temp, u[1] + 1)
    ans = min(ans, temp)

print(ans)