using System;

public class Program

{

    public static void Main()

    {

        const int MaxCols = 8;

const int MaxRows = 8;

​

string newLine;

​

bool charX = false; //First line start with X char

for (int i = 0;i< MaxRows;i++)

{ 

newLine = string.Empty;

charX = !charX; //flip

​

for (int j =0; j<MaxCols;j++)

{

newLine += charX ? "X" : "O"; //decision stucture

charX = !charX; //flip 

}

Console.WriteLine(newLine);

} 

    }

}