import heapq
N = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
hq = []
for i in a:
    heapq.heappush(hq, [i, 0])


for i in b:
    l, c = heapq.heappop(hq)
    heapq.heappush(hq, [l + (i // 2), c + 1])

ans = 0
while hq:
    l, c = heapq.heappop(hq)
    ans = max(ans, c)

print(ans)