Revert "Ruby practice MKS"

This reverts commit 6ea215a08ea3e612f76363be9c322b20cba34d0b.
Revert "Revert "Ruby practice MKS""

This reverts commit 3964021f6cae804f89ef3eee81afa794b02df4fb.
Revert "Revert "Revert "Ruby practice MKS"""

This reverts commit efa24963a3c044f08c0c09a5a3e4b053333a54c4.
working?