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 {
    import scala.annotation.tailrec

    val sc = new java.util.Scanner(System.in)
    val pw = new java.io.PrintWriter(System.out)
    @tailrec
    def output(h: Int = sc.nextInt, w: Int = sc.nextInt): Unit = {
        if( h != 0 && w != 0 ) {
            pw.println("#"*w)
            for(i <- 1 to h-2) pw.println("#"+"."*(w-2)+"#")
            pw.println("#"*w)
            pw.println()
            output()
        }
    }

    output()
    pw.flush
}