import heapq

n = input()
a = map(int, raw_input().split())
b = map(int, raw_input().split())

init = []
for level in a:
    init.append((level, 0))

heapq.heapify(init)
ans = float("inf")

for offset in xrange(-n, 0):
    queue = list(init)

    for i in xrange(offset, offset + n):
        level, battle = heapq.heappop(queue)
        heapq.heappush(queue, (level + b[i] // 2, battle + 1))

    max_battle = 0
    for level, battle in queue:
        max_battle = max(max_battle, battle)

    ans = min(ans, max_battle)

print ans