index나 head 파일에 최신글 수정에 숫자 하나만 바꿔도

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Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 32

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 34

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 35

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 37

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/k9540581/www/index.php:1) in /home/hosting_users/k9540581/www/subhead.sub.php on line 38

이런 오류가 뜨는데 왜 이런건지 알고 싶습니다 도대체 뭐가 문젠가요?????