findCommon ([1, 2, 2], [2, 2, 3]);

##</code><code>##

sub findCommon {
    my @lists = @_;
    my @common;
    
    while (@lists == grep {@$_} @lists) {
        my %hits;
        
        $hits{$_->[0]}++ for @lists;
        
        my $least = (sort keys %hits)[0];
        
        push @common, $least if $hits{$least} == @lists;
        $_->[0] eq $least && shift @$_ for @lists;
    }
    
    return @common;
}