Among the products that are no longer in continuous production, how many of them have their supplier in the USA?
no longer continuous refers to Discontinued = 1; USA refers to Country = 'USA';
SELECT COUNT(T1.Discontinued) FROM Products AS T1 INNER JOIN Suppliers AS T2 ON T1.SupplierID = T2.SupplierID WHERE T2.Country = 'USA' AND T1.Discontinued = 1