import heapq

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

def solve(N, A, B):
    record = N
    BB = B + B
    pq0 = [(a, 0) for a in A]
    heapq.heapify(pq0)
    for i in range(N):
        pq = pq0[:]
        for b in BB[i:i + N]:
            a, n = pq[0]
            heapq.heapreplace(pq, (a + b//2, n + 1))
        max_n = max(n for a, n in pq)
        if max_n < record:
            record = max_n
    return record

print(solve(N, A, B))