from heapq import heappop as hpop, heappush as hpush
from copy import deepcopy as dcp
def solve():
	Q = []
	ans = N = int(raw_input())
	for a in map(int,raw_input().split()):
		hpush(Q,(a,0))
	B = map(int,raw_input().split())
	for i in xrange(N):
		q = dcp(Q)
		for j in xrange(N):
			lv,cnt = hpop(q)
			hpush(q,(lv+B[(j+i)%N]/2,cnt+1))
		ans = min(ans,max(q,key=lambda x:x[1])[1])
	print ans 
solve()