Copy files by their extension

The tool should copy all files from a source folder (including subfolders) to a destination folder. All file types like .DOC, TXT etc. should be stored into a subfolder named by the file extension. All files should get a unique file name, that means that each file should get a new file name with a unique number. Detailed specifications in the attached PDF file. Environment: C# Target platform: Win 7, 8.1, 10 This project is urgent und should start and finished tomorrow.