import heapq as hpq from copy import deepcopy as dcp def solve(): Q = [] ans = N = int(raw_input()) Q = [(a,0) for a in map(int,raw_input().split())] hpq.heapify(Q) B = map(int,raw_input().split()) for i in xrange(N): q = dcp(Q) lv,cnt = hpq.heappop(q) for j in xrange(N): lv,cnt = hpq.heapreplace(q,(lv+B[(j+i)%N]/2,cnt+1)) ans = min(ans,max(q,key=lambda x:x[1])[1]) print ans solve()