use strict;

my $a = "This is a sentence";
my $b = "This is another sentecne";

my @matches = match_words($a,$b);
print join(" ",@matches),"\n";
print scalar(@matches);


sub match_words{
     my @word_list1 = split(/\s+/,$_[0]);
     my @word_list2 = split(/\s+/,$_[1]);

     my $i = 0;
     while(defined($word_list1[$i]) && defined ($word_list2[$i])
		   && $word_list1[$i] eq $word_list2[$i]){
        ++$i;
     }
     return splice @word_list1, 0, $i;
}

__END__
This is
2

##</code><code>##

    my @result = splice @word_list1,0,$i;
    return @result;