while true do
   h, w = gets.split.map(&:to_i)
   if h == 0 && w == 0
      break
   end
   h.times do |i|
      if i == 0 || i == h - 1
         puts "#{"#" * w}"
      else
         puts "##{"." * (w - 2)}#"
      end
   end
   puts ""
end