import heapq


def solve():
    N = int(input())
    A = list(map(int, input().split()))
    B = list(map(int, input().split()))
    z = [0] * N
    C = list(zip(A, z))
    heapq.heapify(C)

    mi = N
    for i in range(N):
        ms = C[:]
        for j in range(i, i + N):
            k = j % N
            l, n = ms[0]
            heapq.heapreplace(ms, (l + B[k] // 2, n + 1))
        ma = max(m[1] for m in ms)
        if ma < mi:
            mi = ma

    print(mi)


if __name__ == '__main__':
    solve()