import heapq
from collections import deque

n=input()
a=map(int,raw_input().split())+[1e9]
b=deque(map(int,raw_input().split()))

max_list=[]

for _ in range(n):
    pq=[(j,0) for j in a]
    heapq.heapify(pq)
    for elevel in b:
        level,cnt=heapq.heappop(pq)
        heapq.heappush(pq,(level+elevel/2,cnt+1))
    max_list.append(max([y for x,y in pq]))
    b.rotate()

print min(max_list)