#!/usr/bin/perl

use strict;
use warnings;

my $file = 'AXP_FACS.DAT';
open my $FH, '<', $file or die "Error opening file: $!";
my @faclist = (<$FH>); % Read all lines into the array
close $FH;
chomp @faclist;        % Remove newlines from each entry.

my @numbers = 1..5000;
foreach my $integer ( @numbers ) {
    unless ( grep { /\b$integer\b/ } @faclist ) {
        print "Not found: $integer\n";
    }
}