use strict;
use warnings;

open my $fh_b, '>', 'input_b.txt' or die "open error: $!";

foreach my $i ( 1 .. 333_333 * 10 ) {
    my $prefix = sprintf('%09s', $i);
    print $fh_b "${prefix}D m\n";
    print $fh_b "${prefix}D n\n";
    print $fh_b "${prefix}D o\n";
    print $fh_b "${prefix}E m\n";
    print $fh_b "${prefix}E s\n";
}

close $fh_b;