def f(a, b)
  _party = a.map.with_index{|v,i| [v, 0, i]}
  b.size.times.map{
    party = _party.dup
    b.each{|enemy|
      lv, cnt, idx = party.min
      party[idx] = [enemy/2 + lv, cnt + 1, idx]
    }
    b.rotate!
    party.max_by{|lv,cnt,idx| cnt}[1]
  }.min
end

N = gets.to_i
A = gets.split.take(N).map(&:to_i)
B = gets.split.take(N).map(&:to_i)

p f(A, B)