use strict;
use warnings;

@array1 = (c,d,e);
@array2 = (e,f,g,h);
@array3 = (a,b,d);
@array4 = (s,g,h,j,k,l)
my (%union, %intersect);
foreach my $e (@array1, @array2) {
    $union{$e}++ && $intersect{$e}++
}
my @intersect = sort keys %intersect;
print FILEOUT "@intersect\n"; #prints intersecting words
print FILEOUT scalar @intersect;


##</code><code>##

foreach(1..4) {
   my (%union, %intersect);
   foreach my $e (@title1, @{"title$_"}) {
      $union{$e}++ && $intersect{$e}++
    }
    my @intersect = sort keys %intersect;
    print FILEOUT "@intersect\n";
    print FILEOUT scalar @intersect;
    print FILEOUT "\n";
}


##</code><code>##

       array1 : array2 : array3 : array4
array1: 10 : 5 : 17 : 2
array2: 5 : 15 : 8 : 1
array3: 17 : 8 : 14 : 6
array4: 2 : 1 : 6 : 19