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;
using System.Text;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                //????????¨??????????????????
                string[] s = Console.ReadLine().Split(' ');
                int high = int.Parse(s[0]);
                int width = int.Parse(s[1]);


                //????????¨????????¨??????0???????????????????????????????????????
                if ((high == 0) && (width) == 0) break;


                for (int i = 0; i < high; i++)
                {
                    for (int j = 0; j < width; j++)
                    {
                        if ((i==0) || (i==high-1) || (j == 0) || (j == width-1))
                            Console.Write("#");
                        else
                            Console.Write(".");
                    }
                    Console.Write("\n");
                }

                Console.Write("\n");

            }
        }
    }
}