import java.util.*;

public class triangle {

    public static void main(String[]args)
    {
        Scanner reader = new Scanner(System.in);

        System.out.print("Rows: ");
        int iRows = reader.nextInt();

        for(int i = 1; i <= iRows; i++)
        {
          printStars(i);

        }

        for(int c = iRows; c >= 0; c--)
        {
            printStars(c);
        }
    }

    public static void printStars(int iStars)
    {
        for(int y = 1; y <= iStars; y++)
        {
            System.out.print("@");
        }

        System.out.print("\n");
    }


}