rewrite.pl

#!/usr/bin/perl
use strict;
use warnings;

sub lines($);

while (<>) {
  my ($x, $y) = split;
  my $xs = lines $x;
  my $ys = lines $y;
  while (@$xs || @$ys) {
    print shift @$xs if @$xs;
    print "\t";
    print shift @$ys if @$ys;
    print "\n";
  }
}

sub lines($) {
  my $line_ = shift;
  my @lines_ = split /。/, $line_;
  chomp @lines_;
  return \@lines_;
}