Simplify Path

You are given a full path that starts with /.
Change it to the shortest clean path using these rules:
• . means stay in the same folder.
• .. means go up one folder (if possible).
• Many slashes // or /// count as one slash.
• Names like ... or .... are just normal folder names.

The final clean path must:
1. Start with one slash /.
2. Have folder names separated by one slash.
3. Not end with a slash unless it is just /.
4. Have no . or .. left.
Return this clean path.