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

my $NumbersList                = 'NumbersList';
my $LookingForTheseNumbersList = 'LookingForTheseNumbersList';


open LOOKINGFORTHESENUMBERSLIST, '<', $LookingForTheseNumbersList or die "Cannot open '$LookingForTheseNumbersList' because: $!";

my %data;
while ( <LOOKINGFORTHESENUMBERSLIST> ) {
    if ( /^(\d+)/ ) {
        $data{ $1 } = [];
        }
    }
close LOOKINGFORTHESENUMBERSLIST;


open NUMBERSLIST, '<', $NumbersList or die "Cannot open '$NumbersList' because: $!";

while ( <NUMBERSLIST> ) {
    if ( /^(\d+)\s+(\d+)/ && exists $data{ $1 } ) {
        push @{ $data{ $1 } }, $2;
        }
    }
close NUMBERSLIST;


for my $number ( sort { $a <=> $b } keys %data ) {
    print "$number $_\n" for @{ $data{ $number } };
    }

exit 0;