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;
using System.Threading.Tasks;

namespace ITP1
{
    class ITP1_5_B
    {
        static void Main(string[] args)
        {
            int h, w;
            List<int> dataSet;

            while (true)
            {
                dataSet = Console.ReadLine().Split().Select(int.Parse).ToList();
                h = dataSet[0];
                w = dataSet[1];

                if (h == 0 && w == 0)
                {
                    break;
                }

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