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 C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
namespace ITP1_5_B
{
    class Problem
    {

        public static List<string[]> getinputdata (){

            List<string[]> list_temp = new List<string[]>();
            string strdata = Console.ReadLine ();

            while (strdata!=null) {

                string[] s_temp = strdata.Split (' ');

                list_temp.Add (s_temp);

                strdata = Console.ReadLine ();

            }

            return list_temp;
        }


        public static void DrawRectangle (int h,int w){

            //????±?????????°??????????????????
            for (int j = 0; j < h; j++)
            {
                
                //???????????¨??????????????????????????????
                if (j == 0 || j == h - 1)
                {
                    string strdata = new string('#', w);
                    Console.WriteLine(strdata);
                }
                else
                {
                    string strdata = "#" + new string('.', w - 2) + "#";
                    Console.WriteLine(strdata);
                }
                   

      
            }

            Console.WriteLine();
        }

        public static void Main (string[] args)
        {
            List<string[]> list_result = new List<string[]>();
            list_result = getinputdata ();

            int H;
            int W;

            for (int i = 0; i < list_result.Count-1; i++)
            {
                H = int.Parse(list_result[i][0]);
                W = int.Parse(list_result[i][1]);

                DrawRectangle(H, W);
            }

        }
    }
}