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

.#.

.#.#

.#.

.#.#.

.#.#.#

.#.#.

.#.#.#

.#.#.

.

.#.

.

.

.#

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