### main

while true
  n = gets.strip.to_i
  break if n == 0

  as = gets.strip.split(' ').map{|s| s.to_i}.sort{|a, b| b <=> a}
  bs = gets.strip.split(' ').map{|s| s.to_i}.sort{|a, b| b <=> a}

  done = false
  win = 0

  for k in (1...n)
    if as[k - 1] > bs[k - 1]
      win += 1
      if win * 2 > k
        done = true
        puts k
      end
    end
  end

  if ! done
    puts 'NA'
  end
end