#!/usr/bin/perl

open FILE1,"./a.txt" or die "Cannot open a.txt";
open FILE2,"./b.txt" or die "Cannot open b.txt";
open FILE3,">./r.txt" or die "Cannot create r.txt";

while (<FILE1>)
{
  chomp;
  /[^\ ]*$/;
  $common = $&;
  $begin = $`;
  chop $begin;
  $array{$common} = $begin;
}
close FILE1;
while (<FILE2>)
{
  chomp;
  /^[^\ ]*\ /;
  $common = $&;
  chop $common;
  $end = $';
  print FILE3 "$array{$common} $common\zz$end" if exists $array{$common};
}
close FILE2;
close FILE3;