# coding: utf-8
import heapq
N = int(raw_input())
A = map(int, raw_input().split())
B = map(int, raw_input().split())

Aheap = []
for i in range(len(A)):
	heapq.heappush(Aheap, (A[i], 0))

B = [int(b)/2 for b in B]
B_ = list(B)
B.extend(B_)

ans = int(1e9+7)
for i in range(len(B_)):
	a = list(Aheap)
	for j in range(len(B_)):
		lv, c = a[0]
		#print str(lv) + ' ' + str(c)
		heapq.heapreplace(a, (lv+B[i+j], c+1))
		#print a
	ans=min(ans, max(c for lv, c in a))

print ans