Write SQL query to solve given problem: How many products that take more than 2 days to make are out of stock?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(T2.ProductID) FROM ProductVendor AS T1 INNER JOIN Product AS T2 ON T1.ProductID = T2.ProductID WHERE T1.OnOrderQty IS NULL OR T1.OnOrderQty = 0