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 Project
{
	class MainClass
	{
		public static void Main(string[] args)
		{
			while (true)
			{
				string s = Console.ReadLine();
				string[] sar = s.Split(' ');
				int H = int.Parse(sar[0]);
				int W = int.Parse(sar[1]);

				if (H == 0 && W == 0) { break;}

				char[] c = new char[W];
				for (int i = 0; i < W; i++)
				{
					c[i] = '.';
				}
				c[0] = '#';
				c[W - 1] = '#';

				for (int i = 0; i < H; i++)
				{
					for (int j = 0; j < W; j++)
					{
						if (i == 0 || i == H - 1) { Console.Write("#");}
						else { Console.Write(c[j]); }
					}
					Console.Write("\n");
				}
				Console.Write("\n");
			}
		}
	}
}