the n can be zero, specifying a minimum of zero matches for subexpression X.
To ask for a match with subexpression X at least n times, use
(Notice that the comma is immediately followed by the right brace.)
For example, this
Rats!! Rats!!!! Rats!!!!!!
Write the expression that matches two or more groups of Rats! such as Rats! Rats! or Rats! Rats! Rats! Rats!