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 JAVA (judge verdict: Accepted)

import java.util.Scanner;

class Main{
	public static void main(String[] args){
		
		Scanner sc = new Scanner(System.in);
		
		StringBuilder all = new StringBuilder();
		StringBuilder out = new StringBuilder();
		
		while(true){
			
			int h = sc.nextInt();
			int w = sc.nextInt();
			
			if((h + w) <= 0){break;}
			
			
			for(int t = 0; t < w; t++){
				out = out.append("#");
			}
			out = out.append("\n");
			
			
			
			for(int j = 0; j < (h-2); j++){
				out = out.append("#");
				for(int i = 0; i < (w-2); i++){
						out = out.append(".");
					}
				out = out.append("#");
				out = out.append("\n");
			}
			
		
			for(int b = 0; b < w; b++){
				out = out.append("#");
			}
			
			out = out.append("\n");
		
			all = all.append(out + "\n");
			out.delete(0, out.length());
			
		}
		
		System.out.print(all);
	}
}