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

ans = N
for i in xrange(N):
   curB=B[i:]+B[:i]
   curAns = 0
   pq = zip(A,[0 for i in range(N)])
   heapify(pq)
   for b in curB:
      level,num=heappop(pq)
      heappush(pq,(level+b/2,num+1))
      curAns = max(curAns,num+1)
   ans = min(ans,curAns)
print ans