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.StdIn.readLine

object Main {
  def main(args: Array[String]) {
    def printFrame: Unit = {
      val Array(a, b) = readLine().split(" ").map(_.toInt)
      if(a != 0 && b != 0) {
        for(i <- 1 to a) {
          if(i == 1 || i == a) println("#" * b)
          else println("#" + "." * (b - 2) + "#")
        }
        println()
        printFrame
      }
    }

    printFrame
  }
}