#!/usr/bin/env python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from heapq import heapify, heappushpop

N = int(readline())
A = tuple(map(int, readline().split()))
B = tuple(map(int, readline().split())) * 2


def solve(i):
    mask = (1 << 15) - 1
    q = [x << 15 for x in A]
    heapify(q)
    ret = 0
    for b in B[i: i + N]:
        x = q[0]
        lv, cnt = x >> 15, x & mask
        lv += b // 2
        cnt += 1
        if ret < cnt:
            ret = cnt
        x = (lv << 15) + cnt
        heappushpop(q, x)
    return ret


answer = min(solve(i) for i in range(N))
print(answer)