use strict;
use warnings;

use List::Compare;

my @S1 = ( 'G1', 'G3', 'G5' );
my @S2 = ( 'G1', 'G3', 'G5', 'G7', 'G12' );
my @S3 = ( 'G1', 'G5' );

my @A = (\@S1, \@S2, \@S3);

my $lc = List::Compare->new('--unsorted', @A);

my @intersection = $lc->get_intersection;

print "intesection is @intersection\n";