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 _1_5_B
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                string[] str = Console.ReadLine().Split(' ');
                int a = int.Parse(str[0]);
                int b = int.Parse(str[1]);
                if (a == 0 || b == 0) break;
                for(int i0 = 0; i0 < b; i0 += 1)
                {
                    Console.Write("#");
                }
                Console.Write("\n");
                if (a == 1) break;
                int count = 0;
                for(int i1 = 0; i1 < a - 2; i1 += 1)
                {
                    if (count == 0) Console.Write("#");
                    for (int i2 = 0; i2 < b - 2; i2 += 1)
                    {
                        Console.Write(".");
                    }
                    Console.WriteLine("#");
                }
                for (int i3 = 0; i3 < b; i3 += 1)
                {
                    Console.Write("#");
                }
                Console.WriteLine("\n");
            }
        }
    }
}