from heapq import heappush, heappop

INF = 1 << 60
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))


def solve(p: int):
    q = []  # (レベル, 戦闘回数)
    for a in A:
        heappush(q, (a, 0))

    for b in B[p:] + B[:p]:
        lv, cnt = heappop(q)
        heappush(q, (lv+(b//2), cnt+1))

    return max(cnt for _, cnt in q)


ans = INF
for i in range(N):
    ans = min(ans, solve(i))

print(ans)