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 _5_B

class Program
{
    static void Main(string[] args)
    {
        while (true)
        {
            //???????????????3????????????????????????????????????
            string readData = Console.ReadLine();

            //???????????¨??????????????????????????????H,W???????????????????????????
            string[] readDataValues = readData.Split(' ');
            int H = int.Parse(readDataValues[0]);
            int W = int.Parse(readDataValues[1]);

            //3??\?????????300??\????????´?????????
            if (3 > H || W > 300)
            {
                break;
            }

            for (int num = 1; num <= H; num++)
            {

                for (int digital = 1; digital <= W; digital++)
                {

                    //1???????????¨???
                    if (num == 1)
                    {
                        Console.Write("#");
                    }
                    //1??????????????¨???                
                    else if (digital == 1)
                    {
                        Console.Write("#");
                    }
                    //1?????????????????¨???
                    else if (digital == W)
                    {
                        Console.Write("#");
                    }
                    //1?????????????????¨???
                    else if (num == H)
                    {
                        Console.Write("#");
                    }
                    //????????\????????¨???
                    else
                    {
                        Console.Write(".");
                    }


                }
                //1???????????£??????????????????
                Console.WriteLine();
            }
            Console.WriteLine();
        }
    }
}