|
Лимит времени 2000/4000/4000/4000 мс. Лимит памяти 65000/65000/65000/65000 Кб.
Сложность Альфа
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.
|