n=gets.to_i
mod=2000
a=gets.split.map{|i|i.to_i*mod}.sort+[1e9]
b=gets.split.map{|i|i.to_i/2}
p (1..n).map{|i|
  pq=a.dup
  b.rotate(i).each{|e|
    l=pq.shift
    up=l+e*mod+1
    pq.insert((0..n-1).bsearch{|x|pq[x]>=up},up)
  }
  pq[0..-2].map{|x|x%mod}.max
}.min