import heapq
N = int(input())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
ans = 10 ** 9 + 7
for i in range(N):
	pq = [(j,0) for j in A]
	heapq.heapify(pq)
	battle = 0
	for j in range(N):
		p = heapq.heappop(pq)
		next = (p[0] + (B[(i + j) % N]//2),p[1] + 1)
		battle = max(battle,next[1])
		heapq.heappush(pq,next)
	ans = min(ans,battle)
print(ans)