from heapq import heappush,heappop
N=int(raw_input())
A=map(int, raw_input().split())
B=map(int, raw_input().split())

ans = N
for i in range (N):
   pq=[]
   curAns = 0
   for a in A:
      heappush(pq,(a,0))
   for j in range(N):
      ind=(i+j)%N
      level,num=heappop(pq)
      heappush(pq,(level+B[ind]/2,num+1))
      curAns = max(curAns,num+1)
   ans = min(ans,curAns)
print ans