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 u, nl = System.getProperty("line.separator");
        StringBuilder
            p = new StringBuilder(1000),
            d = (new StringBuilder(100)).append("."),
            s = (new StringBuilder(100)).append("#"),
            k = new StringBuilder(100);
        Scanner r = new Scanner(System.in);
        int h, w, ww;
        d.append(d).append(d).append(d).append(d);
        s.append(s).append(s).append(s).append(s);
        ww = d.length();
        while (0 != ((h = r.nextInt()) | (w = r.nextInt()))) {
            while (w > ww) {
                d.append(d);
                s.append(s);
                ww = d.length();
            }
            p.append(u = s.substring(0, w)).append(nl);
            k.setLength(0);
            k.append(d.substring(0, w)).append(nl)
            .replace(0, 1, "#").replace(w - 1, w, "#");
            while (2 != h--) {
                p.append(k);
            }
            p.append(u).append(nl).append(nl);
        }
        System.out.print(p);
    }
}