Nice job! Now let's explore the product demand for each country.
In the last exercise, we created a variable named countries_without_PC that stores the names of the countries for all cities that are not production centers. The quantity of goods transported to each city is recorded in the quantity column.
Display the quantity of goods that must be transported by company_a (the first member of the companies list) to each city that is not a production center. Store the result in a variable named quantity_without_PC.
(Note: The rationale here is that if a city is a production center, we don't need to transport goods to it.)
