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;


namespace ConsoleApplication13
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true) {
                String[] s = Console.ReadLine().Split(' ');
                int H = int.Parse(s[0]);
                int W = int.Parse(s[1]);

                if (H == 0 && W == 0) break;
            
                int i = 0;
                while (true)
                {
                    if (i == H) break;
                    if (i == 0 || i == H - 1)
                    {
                        for (int x = 0; x < W; x++)
                        {
                            Console.Write("#");

                        }
                    }
                    else
                    {
                        Console.Write("#");
                        for (int x = 1; x < W-1; x++)
                        {
                            Console.Write(".");

                        }
                        Console.Write("#");
                    }
                    
                    Console.WriteLine();

                    i++;
                }
                Console.WriteLine();


            }

        }
    }
}