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;
namespace CsProgramSpace
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int[]> list = new List<int[]>();
            while(true)
            {
                int[] i = new int[2];
                i = (Console.ReadLine().Split(' ').Select(_ => int.Parse(_)).ToArray());
                if (i[0] == 0 && i[1] == 0) break;
                list.Add(i);
            }
            foreach(int[] i in list)
            {
                for(int j = 0; j<i[0];j++)
                {
                    for(int k = 0; k<i[1];k++)
                    {
                        if (j == 0 ||j==i[0]-1|| k == 0 || k == i[1] - 1)
                            Console.Write("#");
                        else
                            Console.Write(".");
                    }
                    Console.WriteLine("");
                }
                Console.WriteLine("");
            }
        }
    }
}