htaccess - Redirect a url with multiple slashes (//) to single slash (/)

What is the .htaccess rule to redirect http://ift.tt/2cd4RMY to http://ift.tt/2cd4RMY, or http://ift.tt/2cd4JwM to https://domain.com/a/b/, and in general everything with more than one slash // to single slash /?