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;

class Program
{
    static void Main(string[] args)
    {

        while (true)
        {

            String[] str = Console.ReadLine().Split(' ');

            char[,] ary = new char[int.Parse(str[0]), int.Parse(str[1])];

            if (int.Parse(str[0]) == 0 && int.Parse(str[1]) == 0)
            {
                break;
            }

            for (int i = 0; i < ary.GetLength(0); i++)
            {
                for (int j = 0; j < ary.GetLength(1); j++)
                {
                    if (i == 0 || i + 1 == ary.GetLength(0) || j == 0 || j + 1 == ary.GetLength(1))
                    {
                        Console.Write("#");
                    }
                    else
                    {
                        Console.Write(".");
                    }
                }
                Console.WriteLine();
            }

            Console.WriteLine();
        }
    }
}