We have a tar.xz file that when is decompressed has lots of tar.xz files, and so recursively, so we used the following command to extract them 
```while [ "`find . -type f -name '*.tar.xz' | wc -l`" -gt 0 ]; do find -type f -name "*.tar.xz" -exec tar xf '{}' \; -exec rm -- '{}' \;; done;```
and obtained a file with the flag: INSA{04ebb0d6a87f9771f2eea4dce5b91a85e7623c13301a8007914085a91b3ca6d9}
By fikih888