13240번 - Chessboard 다국어

문제

Write a program that prints a chessboard with N rows and M columns with the following rules:

• The top left cell must be an asterisk (*)
• Any cell touching (left, right, up or down) a cell with an asterisk must be a dot (.)
• Any cell touching (left, right, up or down) a cell with a dot must be an asterisk.

A chessboard of 8 rows and 8 columns printed using these rules would be:

*.*.*.*.
.*.*.*.*
*.*.*.*.
.*.*.*.*
*.*.*.*.
.*.*.*.*
*.*.*.*.
.*.*.*.*

입력

A single line with two integers N and M separated by spaces. The number N will represent the number of rows and M the number of columns. N and M will be between 1 and 10.

출력

Print N lines each containing M characters with the chessboard pattern.

제한

힌트