Problem:
Print a Frame

Draw a frame which has a height of H cm and a width of W cm. For example, the following figure shows a frame which has a height of 6 cm and a width of 10 cm.

##########
#........#
#........#
#........#
#........#
##########

Input

The input consists of multiple datasets. Each dataset consists of two integers H and W separated by a single space.

The input ends with two 0 (when both H and W are zero).

Output

For each dataset, print the frame made of '#' and '.'.

Print a blank line after each dataset.

Constraints

3 ≤ H ≤ 300

3 ≤ W ≤ 300

Sample Input

3 4
5 6
3 3
0 0

Sample Output

####
#..#
####

######
#....#
#....#
#....#
######

###
#.#
###

Solution in Scala (judge verdict: Accepted)

import scala.io.Source

object Main{
  def main(args: Array[String]){
    val list =
      for{
        in <- Source.stdin.getLines.toList
      } yield in

    list.map(_.split(" ").map(_.toInt).toList).init.foreach{ list =>
      val height = list.head
      val width = list.last

      println("#" * width)
      (2 to height-1).foreach{ i =>
        println(s"#${"." * (width - 2)}#")
      }
      println("#" * width)
      println
    }
  }
}