#yuki_9
import heapq

n=int(raw_input())
a=[(int(i),0) for i in raw_input().split()]
b=map(int,raw_input().split())
heapq.heapify(a)

res=n
for i in xrange(n):
 aa=a[:]
 for j in range(i,i+n):
  r=j%n
  x,y=aa[0]
  heapq.heapreplace(aa,(x+b[r]/2,y+1))
 temp=max(z for x,z in aa)
 res=min(res,temp)
print res