n = int(input()) A = list(map(int, input().split())) B = list(map(int, input().split())) B = B+B import heapq m = 1550 ans = 10**18 for i in range(n): q = [] for a in A: q.append(a*m) heapq.heapify(q) for j in range(i, i+n): b = B[j] a = heapq.heappop(q) level, cnt = divmod(a, m) level += b//2 cnt += 1 na = level*m+cnt heapq.heappush(q, na) temp = 0 while q: a = heapq.heappop(q) level, cnt = divmod(a, m) temp = max(temp, cnt) ans = min(ans, temp) print(ans)