Develop a system that calculates usage fees for a storage service!

Problem Statement

Develop a system that calculates usage fees for a storage service! Problem Description You belong to a storage service company and have been asked to create a system that calculates usage fees. Your company provides a storage service that allows users to store and view files. In the storage service, users can perform the following three operations: 'upload and save files', 'delete saved files', and 'update saved files'. The fee is the sum of the storage fee , which is determined by the usage of the storage during the month, and the update fee , which is determined by the sum of the file sizes of the updated files during the month. This service has a free plan that is available free of charge within the restrictions. In the Advanced implementation, a paid plan is added that allows for larger scale service usage. Users initially subscribe to the free plan and can use the service within certain limitations, but when they change to the paid plan, they will be able to use the service beyond