pr-Legolasov

function findId($json_data, $cityName) {
  foreach($json_data[$cityName] as $id => $regionName) {
    if ($id < 0) return $id;
  }
}

var_dump(findId($json_data, 'Абакан'));

RewriteCond %{HTTP_HOST} ^(?>www\.|)([^.]+)\.xn--80ajybdmjbd1a\.xn--p1ai$
RewriteCond %1.%{REQUEST_URI} !^([^.]+)./\1/
RewriteRule ^(.*)$ /%1/$1 [L]