human
Draw a chessboard which has a height of H cm and a width of W cm. For example, the following figure shows a chessboard which has a height of 6 cm and a width of 10 cm.

.#.#.#.#.
.#.#.#.#.#
.#.#.#.#.
.#.#.#.#.#
.#.#.#.#.
.#.#.#.#.#

Note that the top left corner should be drawn by '#'.

Constraints

* 1 ≤ H ≤ 300
* 1 ≤ W ≤ 300

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 chessboard made of '#' and '.'.

Print a blank line after each dataset.

Example

Input

3 4
5 6
3 3
2 2
1 1
0 0

Output

#.#.
.#.#
#.#.

#.#.#.
.#.#.#
#.#.#.
.#.#.#
#.#.#.

#.#
.#.
#.#

#.
.#

#
assistant
#Here is Python code to print a blank line after each dataset.

class PrintAChessboard:
    def output(self, H, W):
        s1 = ""
        s2 = ""
        for w in range(W):
            if w % 2 == 0:
                s1 += "#"
                s2 += "."
            else:
                s1 += "."
                s2 += "#"
        for h in range(H):
            if h % 2 == 0:
                print s1
            else:
                print s2
        print

if __name__ == "__main__":
    pc = PrintAChessboard()
    while True:
        h, w = map(int, raw_input().split())
        if h == 0 and w == 0:
            break
        pc.output(h, w)