Prevent search engines indexing pages with 3 or more forwarslashes in their paths

How can I prevent search engines indexing pages with 3 or more forw开发者_运维百科arslashes in their paths? for example:

www.example.com/about.html ->ok
www.example.com/1/2/3/4/5/test.html -> no index!!!

How should I write the robots.txt? Thanks!

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Try with

User-Agent: *
Disallow: /*/*/*/*

Although I'm not sure all bots support the *.