Regex to match word one or more times in a string

I'm really bad with regex. For the purposes of URI rewriting, I'm trying to figure out how to match a word one or more times in a string.

For example, I want to do something like:

string/string/string/foo/bar => foo/bar
string/string/bazbat => bazbat

Currently I have:

^string/(.*)$ => $1

and that works, but I want to make string/ work for one or more times, not just once.