import heapq N = int(input()) A = list(map(int, input().split())) A.sort() B = [int(x)//2 for x in input().split()]*2 H = [(a,0) for a in A] min_max_cnt = N for i in range(N): h = H[:] for b in B[i:i+N]: s,t = h[0] heapq.heapreplace(h, (b+s, t+1)) max_cnt = max(t for s,t in h) if min_max_cnt > max_cnt: min_max_cnt = max_cnt print(min_max_cnt)