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 in = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		while (in.hasNext()) {
			int lenH = in.nextInt();
			int lenW = in.nextInt();

			if (lenH == 0) {
				break;
			}

			String topBottom = repeat('#', lenW);
			sb.append(topBottom).append("\n");
//			if (lenH > 1) {
			String side = "#" + repeat('.', lenW - 2) + "#";
			for (int i = 0, len = lenH - 2; i < len; i++) {
				sb.append(side).append("\n");
			}
			sb.append(topBottom).append("\n");
//			}

			sb.append("\n");
		}
		System.out.print(sb.toString());
	}

	private static String repeat(char c, int len) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < len; i++) {
			sb.append(c);
		}
		return sb.toString();
	}
}