1에서
Warning: Undefined array key "n" in /users/2019/i1962026/public_html/2022/WebProg/ch08/exam08-07.php on line 17
까지 자연수의 합은
Fatal error: Uncaught Error: Call to undefined function num() in /users/2019/i1962026/public_html/2022/WebProg/ch08/exam08-07.php:18 Stack trace: #0 {main} thrown in /users/2019/i1962026/public_html/2022/WebProg/ch08/exam08-07.php on line 18