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;

class aizu_judge
{
    static void Main(string[] args)
    {
        while(true)
        {
            int[] num = Console.ReadLine().Split().Select(int.Parse).ToArray();
            if (num[0] + num[1] == 0)
                break;


            for (int i = 0; i < num[0]; i++)
            {
                string width = string.Empty;
                if (i == 0 || i == num[0] - 1)
                    width = new string('#', num[1]);
                else if (num[1] > 2)
                    width = "#" + new string('.', num[1] - 2) + "#";

                Console.WriteLine(width);
            }
            Console.WriteLine();
        }
    }
}