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 ITP1_5_B
{
    class Program
    {
        static void Main(string[] args)
        {
            int H, W;
            while(true)
            {
                string[] str = Console.ReadLine().Split(' ');
                H = int.Parse(str[0]);
                W = int.Parse(str[1]);

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

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

                Console.Write("\n");
            }
        }
    }
}