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.Linq;
using System.Text;

namespace ConsoleApplication12
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                var hw = Console.ReadLine().Split().Select(int.Parse).ToArray();
                int h = hw[0];
                int w = hw[1];
                if (h == 0 && w == 0)
                    break;
                for (int a = 0; a < w; ++a)
                {
                    Console.Write("#");
                }
                Console.WriteLine();

                for (int b = 2; b < h; ++b)
                {
                    Console.Write("#");
                    for (int a = 2; a < w; ++a)
                    {
                        Console.Write(".");
                    }
                    Console.WriteLine("#");
                   
                }
                    for (int a = 0; a < w; ++a)
                    {
                        Console.Write("#");
                    }
                    
                Console.WriteLine();
                Console.WriteLine();
                }


            }
        }
    }