#!/usr/bin/perl -w
use strict;
my $targets = '1689 9679 6978 2792 2514 5472 1520 9342 5544 1268 0165 1979 7314 2101 7221 9539 3882 1812';
my $test = "2101";
if ($test =~ /$targets/) {
    print "OK";
}
else {
    print "Not there";
}