I need a tool designed to compare and merge files

I need a tool designed to compare and merge files. I need to parse the information from the three folders. I do not need to synchronize directories, the structure of the three folders is completely different. I need from the first folder, in which there are a lot of files and subdirectories, to delete everything that is in the second folder, in which there are also many files and subdirectories. And then I need to combine them together and compare all this with the third folder.