Warning: session_start(): open(/tmp/sess_7a31c5a251c480be9d7abd86ec41f212, O_RDWR) failed: No space left on device (28) in /data/wiki/inc/init.php on line 239

Warning: session_start(): Failed to read session data: files (path: ) in /data/wiki/inc/init.php on line 239

Warning: Cannot modify header information - headers already sent by (output started at /data/wiki/inc/init.php:239) in /data/wiki/inc/auth.php on line 430

Warning: Cannot modify header information - headers already sent by (output started at /data/wiki/inc/init.php:239) in /data/wiki/inc/Action/Export.php on line 103

Warning: Cannot modify header information - headers already sent by (output started at /data/wiki/inc/init.php:239) in /data/wiki/inc/Action/Export.php on line 103

Warning: Cannot modify header information - headers already sent by (output started at /data/wiki/inc/init.php:239) in /data/wiki/inc/Action/Export.php on line 103
[[http://codeforces.com/contest/1510|Practice link]]