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 C# (judge verdict: Accepted)

using System;

namespace ITP1_5_B {
    class Program {
        static void Main(string[] args) {
            while(true) {
                string[] s = Console.ReadLine().Split(' ');
                int H = int.Parse(s[0]);
                int W = int.Parse(s[1]);
                if(H == 0 && W == 0) break;
                string a = new string('#', W);
                string b = new string('.', W - 2);
                for(int i = 0; i < H; i++) {
                    if(i == 0) {
                        Console.WriteLine(a);
                    } else if(i == H - 1) {
                        Console.WriteLine(a);
                    } else {
                        Console.WriteLine("#" + b + "#");
                    }
                }
                Console.Write("\n");
            }
        }
    }
}