chomp(my @lines = <DATA>);

my %seen;

for my $line1 (@lines) {
    for my $line2 (grep $_ ne $line1, @lines) {
        if (1 < matches($line1, $line2)) {
            $seen{ join ' and ', sort $line1, $line2 } = 1;
        }
    }
}

print "$_\n" for keys %seen;

sub matches {
    my ($line1, $line2) = @_;
    my %words1 = map {$_ => 1} split /_/, $line1;

    my $matches = 0;
    $matches += ($words1{$_}||0) for split /_/, $line2;
    return $matches;
}