use warnings;
use strict;
$_ = '1: A silly sentence (495,a) *BUT* one which will be useful. (3)';
my $pattern = <STDIN>; 
##</code><code>##

if (/$pattern/){ 
##</code><code>##

 
  print "words $pattern\n";
  print "\$1 morewords\n";
  print "\$2 morewords\n";
  print "\$seewhereimgoing\n";
}

##</code><code>##

if /$pattern/{
  print "$$i\n";
  $i++;
}

##</code><code>##

$_ = '1: A silly sentence (495,a) *BUT* one which will be useful. (3)';

print "Enter a regular expression: ";
my $pattern = <STDIN>;
chomp $pattern;
if (my @matches = /$pattern/) {
    for my $i (0..@-) {
        print "$i: $matches[$i]\n";
    }
}

##</code><code>##

Enter a regular expression: ([a-z]+?)(.*?)([a-z]+?) 
0: s
1: 
2: i
Use of unitialized value in concatenation (.) or string at exp3.pl line 14, <STDIN> line 1.
3. 
Use of unitialized value in concatenation (.) or string at exp3.pl line 14, <STDIN> line 1.
4: