def f(a, b)
  _party = a.map{|v| v * MOD}.sort
  troop = b.map{|v|v/2}
  troop.size.times.map{
    party = _party.dup
    troop.each{|elv|
      lv_cnt = party.shift + elv * MOD + 1
      nth = party.bsearch_index{|v| v >= lv_cnt} || party.size
      party.insert(nth, lv_cnt)
    }
    troop.rotate!
    party.map{|v| v % MOD}.max
  }.min
end

N = gets.to_i
A = gets.split.take(N).map(&:to_i)
B = gets.split.take(N).map(&:to_i)
MOD = 2000
p f(A, B)