loop do
  h, w = gets.chomp.split(/\s/).map(&:to_i)
  break if h == 0 && w == 0
  h.times do |i|
    case i
    when 0, h-1
      puts "#" * w
    else
      puts "#" + "." * (w-2) + "#"
    end
  end
  puts ''
end