from heapq import heappush, heappop

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
ans = 10**18

for i in range(N):
    pq = []
    
    for j in range(N):
        heappush(pq, (A[j], 0))
    
    for j in range(N):
        level, cnt = heappop(pq)
        level += B[(i+j)%N]//2
        cnt += 1
        heappush(pq, (level, cnt))
    
    ans = min(ans, max(cnt for _, cnt in pq))

print(ans)