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;
using System.Collections.Generic;
using System.Linq;

namespace ITP1_5_B
{
    class Program
    {
        static void Main(string[] args)
        {
            var list = new List<byte[]>();
            string input;
            while ((input = Console.ReadLine()) != "0 0")
                list.Add(input.Split(' ').Select(x => Convert.ToByte(x)).ToArray());
            foreach(var l in list)
            {
                //if (l[0] < 3 || 100 < l[1]) continue;
                string hframe = new string('#', l[1]);                
                Console.WriteLine(hframe);
                for(int i = 0; i < l[0] - 2; i++)
                {
                    string hollow = new string('.', l[1] - 2);
                    Console.WriteLine("#" + hollow + "#");
                }
                Console.WriteLine(hframe + "\n");                
            }           
        }
    }
}