$matchsticks = intval(trim(fgets(STDIN)));
      $max_number = "";
      if ($matchsticks == 1) exit("1");
      if ($matchsticks == 3) exit("7");
      while($matchsticks > 0) {
        $matchsticks -= 2;
        $max_number .= 1;
      }
      echo intval($max_number);