from heapq import heappop, heappush

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

res = float('inf')
for i in range(N):
    h = []
    cnt = 0
    for j in range(N):
        heappush(h,(A[j],0))
    for j in range(N):
        b = B[(i+j)%N]
        lev, num = heappop(h)
        cnt = max(cnt,num+1)
        heappush(h,(lev+b//2,num+1))
    res = min(res, cnt)
print(res)