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 Python3 (judge verdict: Accepted)

while True:
    H, W = map(int, input().split())

    # H = 0 かつ W = 0 のとき終了する
    if H == 0 and W == 0:
        break

    for i in range(H):
        if i == 0 or i == H - 1:
            # 1 行目と H 行目は # のみ
            for j in range(W):
                print('#', end='')
        else:
            # 2 ~ H - 1 行目は 1 列目と W 列目が # でそれ以外は . となる
            for j in range(W):
                if j == 0 or j == W - 1:
                    print('#', end='')
                else:
                    print('.', end='')
        print()

    # データセットごとに改行する
    print()