n=int(input())
a=list(map(int, input().split()))
b=list(map(int, input().split()))
b=b+b
import heapq
ans=n
for i in range(n):
    que=[[x, 0] for x in a]
    heapq.heapify(que)
    for x in b[i:i+n]:
        p=heapq.heappop(que)
        heapq.heappush(que, [p[0]+x//2, p[1]+1])
    mx=0
    for p in que:
        mx=max(mx, p[1])
    ans=min(ans, mx)
print(ans)