import heapq
N = int(input())
lsA = list(map(int,input().split()))
lsB = list(map(int,input().split()))
#N**2logN
ans = float('INF')
for st in range(N):
    h = [(i,0) for i in lsA]
    heapq.heapify(h)
    for i in range(N):
        lv,times = heapq.heappop(h)
        lv += lsB[(st+i)%N]//2
        heapq.heappush(h,(lv,times+1))
    cnt = 0
    for i in range(N):
        lv,times = heapq.heappop(h)
        cnt = max(cnt,times)
    ans = min(cnt,ans)
print(ans)