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;

namespace rensyuu1
{
    class Program
    {
        public static void Main()
        {
            while (true)
            {
                string[] num = Console.ReadLine().Trim().Split(' ');
                int h = int.Parse(num[0]);
                int w = int.Parse(num[1]);
                if (h == 0 && w == 0) break;
                string str1 = new string('#',w);
                string str2 = new string('.',w-2);
                Console.WriteLine(str1);
                for(int i =0; i < h-2; i++)
                {
                    Console.WriteLine("#{0}#",str2);
                }
                Console.WriteLine(str1);
                Console.WriteLine();

            }

        }
    }
}