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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) throws IOException {

        BufferedReader std = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        while(true){
            String data[] = std.readLine().split(" ");
            int a = Integer.parseInt(data[0]);
            int b = Integer.parseInt(data[1]);
            if(a == 0 && b == 0) break;
            
            for(int i = 0; i < a; i++){
                for(int j = 0; j < b; j++){
                    if(i == 0 || i == a-1 || j == 0 || j == b-1)
                        sb.append("#");
                    else
                        sb.append(".");
            }
                sb.append("\n");
        }
            sb.append("\n");

    }
        System.out.print(sb);
    }
}