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.Linq;

class PG{
    static void Main(string[] args){
        while(true){
            int[] nums=Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            if(nums[0]==0&&nums[1]==0){
                break;
            }
            for(int i=0;i<nums[0];i++){
                for(int j=0;j<nums[1];j++){
                    if(i==0||i==nums[0]-1||j==0||j==nums[1]-1){
                        Console.Write("#");
                    }else{
                        Console.Write(".");
                    }
                }
                Console.WriteLine();
            } 
            Console.WriteLine();
        }
    }
}