my $last1;
my $last2;

while ($content =~ /($word)/g) {
   my $word = $1;

   ++$hash{               $word };
   ++$hash{       "$last1 $word"} if defined $last1;
   ++$hash{"$last2 $last1 $word"} if defined $last2;

   $last2 = $last1;
   $last1 = $word;
}