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]) = {
      var n = readLine.split(" ").map(_.toInt)
      while( n(0) != 0 || n(1) != 0) {
        println("#"*n(1))

        (2 to n(0)-1).foreach(s=> { print("#");print("."*(n(1)-2));print("#\n") })

        if(n(0)>1) {
          println("#"*n(1))
        }
        println("")
        n = readLine.split(" ").map(_.toInt)
      }
  }
}