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Chessboard Pattern

Section problems

• Making Potions
• Santa Gifts
• Chessboard Pattern
• Galls village
• Sequence
• Bishops
• Polygons
• String manipulations
• Lawyers Council
• Math and Soldiers
• Many-coloured roads

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Time limit 2000/4000/4000/4000 ms. Memory limit 65000/65000/65000/65000 Kb. Difficulty Alpha

A chessboard pattern is a pattern that satisfies the following conditions:

• The pattern has a rectangular shape.
• The pattern contains only the characters '.' (a dot) and 'X' (an uppercase letter X).
• No two symbols that are horizontally or vertically adjacent are the same.
• The symbol in the lower left corner of the pattern is '.' (a dot).

You are given two numbers. N is a number of rows and M is a number of columns. Write a program that generates the chessboard pattern with these dimensions, and outputs it.

Input
The first line contains two numbers N and M (1 ≤ N ≤ 50, 1 ≤ M ≤ 50) separated by a whitespace.
Output
Output should contain N lines each containing M symbols that correspond to the generated pattern. Specifically, the first character of the last row of the output represents the lower left corner (see example 1).

Input 1 Input 2 Input 3
8 8
3 1
1 20
Output 1 Output 2 Output 3
X.X.X.X.
.X.X.X.X
X.X.X.X.
.X.X.X.X
X.X.X.X.
.X.X.X.X
X.X.X.X.
.X.X.X.X
.
X
.
.X.X.X.X.X.X.X.X.X.X

Для отправки решений необходимо выполнить вход.

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