import heapq
import copy
# data = LV * 3000 + battles
N=int(raw_input())
baseQ=[]
A=map(int,raw_input().split())
B=map(int,raw_input().split())
for i in xrange(N):
  heapq.heappush(baseQ,A[i]*3000)
minMaxBattle=10**8
for j in xrange(N):
  q=copy.deepcopy(baseQ)
  for k in xrange(N):
    h=heapq.heappop(q)
    h+=int(B[k]/2)*3000+1
    heapq.heappush(q,h)
  maxBattle=0
  for k in xrange(N):
    maxBattle=max(maxBattle,q[k]%3000)
  minMaxBattle=min(minMaxBattle,maxBattle)
print minMaxBattle