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.*;
import java.lang.*;
import java.io.*;

class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String nl = System.getProperty("line.separator");
		StringBuilder p = new StringBuilder(1000);
		StringBuilder d = new StringBuilder(".");
		StringBuilder s = new StringBuilder("#");
		Scanner r = new Scanner(System.in);
		int h, w, i, j, ww;
		String t;
		for (i = 0; i < 6; ++i) {
			d.append(d);
			s.append(s);
		}
		ww = d.length();
		while ((h = r.nextInt()) + (w = r.nextInt()) > 0) {
			while (w > ww) {
				d.append(d);
				s.append(s);
				ww += ww;
			}
			p.append(s.substring(0,w));
			p.append(nl);
			t = d.substring(0, w - 2);
			for (i = 2; i < h; ++i) {
				p.append('#');
				p.append(t);
				p.append('#');
				p.append(nl);
			}
			p.append(s.substring(0,w));
			p.append(nl);
			p.append(nl);
		}
		System.out.print(p);
	}
}