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 std 
{
    public class MainClass 
    {
        public static void Main() 
        {
            while(true) 
            {
                var input = Console.ReadLine().Split(' ');
                int h = int.Parse(input[0]);
                int w = int.Parse(input[1]);
                if (h <= 0 || w <= 0) {
                    break; 
                }
                string frame = new string('#', w);
                string mid = "#" + new string('.', w -2) + "#";

                Console.WriteLine(frame);
                for (int i = 0; i < h -2; i++) {
                    Console.WriteLine(mid); 
                }
                Console.WriteLine(frame);
                Console.WriteLine();
            }
        }
    }
}