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.collection.mutable.ListBuffer
import scala.io.StdIn

object Main extends App {

  var temp = Array(-1, -1)
  val buff = new ListBuffer[(Int, Int)]
  while(temp(0) != 0 && temp(1) != 0){
    temp = StdIn.readLine().split(' ').map(_.toInt)
    buff += ((temp(0), temp(1)))
  }

  val result = buff.dropRight(1).map { case (h, w) =>
    (0 until h).map { j =>
      if(j == 0 || j == h - 1){
        Array.fill(w)("#").mkString("")
      } else {
        val temp = Array.fill(w)(".")
        temp(0) = "#";temp(w-1) = "#";
        temp.mkString("")
      }
    }.mkString(f"%n")
  }
  println(result.mkString(f"%n%n"))
  println("")
}