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 AOJ
{
    class Program
    {
        static void Main(string[] args)
        {
            for (; ; )
            {
                var inputLine = Console.In.ReadLine();
                var inputs = inputLine.Split(new char[] { ' ', '\t', '　' });
                if (inputs.Length != 2)
                {
                    return;
                }

                var H = int.Parse(inputs[0]);
                var W = int.Parse(inputs[1]);
                if (H == 0 && W == 0)
                {
                    break;
                }

                for (int ih = 0; ih < H; ++ih)
                {
                    bool onBorderH = false;
                    if (ih == 0 || ih == H - 1)
                    {
                        onBorderH = true;
                    }
                    for (int iw = 0; iw < W; ++iw)
                    {
                        bool onBorderW = false;
                        if (iw == 0 || iw == W - 1)
                        {
                            onBorderW = true;
                        }
                        if (onBorderH || onBorderW)
                        {
                            Console.Write("#");
                        }
                        else
                        {
                            Console.Write(".");
                        }
                    }
                    Console.WriteLine();
                }
                Console.WriteLine();
            }
        }
    }
}