Chess Model#593

Chess Model

1 second

64 megabytes

Very easy

The Chessboard model must satisfy the following conditions:

The model is rectangular in shape.
It consists only of the symbols '.' (dot) and 'X' (capital Latin X).
No two adjacent symbols, either horizontally or vertically, are the same.
The symbol in the bottom left corner of the model must be '.' (dot).

You are given two numbers: $N$ — the number of rows, and $M$ — the number of columns. Write a program that generates a chessboard model following these rules and outputs it.

Input

The first line of the input file contains two numbers, $N$ and $M$ ( $1 \leq N \leq 50$ 1 \leq N \leq 50, $1 \leq M \leq 50$ 1 \leq M \leq 50), separated by a space.

Output

The output should contain $N$ rows. Each row must have $M$ symbols according to the generated pattern. In particular, the first symbol of the last row corresponds to the bottom left corner (see example).

Examples

Example 1