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

my $OUTPATH='';
my $A='';
my $B='';
my $C='';

my %index;
open(my $temp_fh, '<', "$OUTPATH/$B") or die("Can't open $B ($!)\n");
MAINLOOP:
while(my $line=<$temp_fh>)
{
  while($line=~/(\d+)/gc)
  {
    my $value=$1;
    $value+=0;
    next if(exists($index{$value}));
    $index{$value}=$line;
    next MAINLOOP;
  }
}
close($temp_fh);

open(my $out_fh, '>', "$OUTPATH/$C") or die("Can't open $C ($!)\n");
open(my $in_fh,  '<', "$OUTPATH/$A") or die("Can't open $A ($!)\n");
while(my $line = <$in_fh>)
{
  my $value=substr($line,0,20);
  $value+=0;
  
  if(exists($index{$value}))
  {
    print $out_fh $index{$value};
    next;
  }
  
  print $out_fh $line;
}
close($in_fh);
close($out_fh);