import sys
input = sys.stdin.readline
from heapq import *
from copy import deepcopy

n = int(input())
ans = 1 << 30
p = [(l, 0) for l in map(int, input().split())]
heapify(p)
enemies = list(map(int, input().split()))
for s in range(n):
	party = deepcopy(p)
	for i in range(n):
		l, t = heappop(party)
		heappush(party, (l + enemies[(s + i) % n] // 2, t + 1))
	ans = min(ans, max(x for _, x in party))
print(ans)