Hesham ELMAHDY

when I run:
`gem install rails`

I got this error:

ERROR: Could not find a valid gem 'rails' (>= 0), here is why:

Unable to download data from https://rubygems.org/ - Errno::ETIMEDOUT: Operation timed out - connect(2) for "s3.amazonaws.com" port 443 (https://api.rubygems.org/la...

What should I do now?