Top Customer per Region

For each region return the customer with the highest total order amount (customer and total). Order by region.

Table schema

Orders(id INT PRIMARY KEY, customer VARCHAR(20), region VARCHAR(10), amount INT)

Sample data

id | customer | region | amount
1 | A | East | 100
2 | B | East | 150
3 | C | West | 80
4 | A | East | 30