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 {
  def main(args: Array[String]): Unit = {
    val in = new java.util.Scanner(System.in)
    rec(in)
  }
  def rec(in:java.util.Scanner):Unit ={
    val a = in.nextInt
    val b = in.nextInt
    if(a == 0 & b == 0) return
    for(i <- 1 to a){
      for(j <- 1 to b){
        if(i ==1 || j == 1 || i == a || j == b){
          printf("#")
        }else{
          printf(".")
        }
      }
      println("")
    }
    println("")
    rec(in)
  }
}