Request for Review: Challenge: Building and Organizing Complex Queries - Alternative solution

Hi,

For the challenge Building and Organizing Complex Queries , I was able to come up with the code below.THis is different from the given solution and it worked on checking. I was hoping for some feedback on this. Thank You!

WITH total_customer_group AS 
    (SELECT 
    c.country, c.first_name|| ' '||c.last_name AS customer_name,       SUM(i.total) AS total_amount
         FROM customer AS c 
         INNER JOIN invoice as i 
         ON c.customer_id = i.customer_id
         GROUP BY 2
         )

SELECT 
    t.country, t.customer_name,
    MAX(t.total_amount) AS total_purchased 
    FROM total_customer_group AS t
    GROUP BY 1
    ORDER BY 1,3 DESC