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;

class Program
{
	static void Main()
	{
		string D;
		while ((D = Console.ReadLine()) != "0 0")
		{
			string s = "", t = "";
			string[] sD = D.Split(' ');
			int H = int.Parse(sD[0]), W = int.Parse(sD[1]);
			for (int i = 0; i < W; i++)
			{
				if (i == 0 || i == W - 1)
				{
					t += "#";
				}
				else
				{
					t += ".";
				}
				s += "#";
			}
			for (int i = 0; i < H; i++)
			{
				if (i == 0 || i == H - 1)
				{
					Console.WriteLine(s);
				}
				else
				{
					Console.WriteLine(t);
				}
			}
			Console.WriteLine();
		}
	}
}