my $test_str = "1 text text text 2 text 3 ";
my $test_out = q{};

my $sec_num_comb_pat = $empty_str;
$sec_num_comb_pat .= '^(([0-9]+)(?![^0-9]*[0-9]))';
my $sec_num_rx = qr{$sec_num_comb_pat}xms;

if ( $test_str =~ m{($sec_num_rx)}xms ) {
  $test_out = $1;
}

print "\$test_out\n" . $test_out . "\n";

##</code><code>##

foreach (@test) {
  @test_filtered=grep{/^(([0-9]+)(?![^0-9]*[0-9]))/xsm} @test; 
}