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)

object Main extends App {
  val scanner = new java.util.Scanner(System.in)

  val data = Iterator.continually {
    val H  = scanner.nextInt()
    val W  = scanner.nextInt()

    (H, W)
  }

  val outputs = data.takeWhile(_ != (0, 0)).map {
    case (h, w) =>
      s"${"#" * w}\n" +
        s"#${"." * (w-2)}#\n" * (h-2) +
        s"${"#" * w}\n"
  }

  outputs.foreach(println)
}