Finally 18🎉

SELECT * FROM gallery2 WHERE topic_id="4278" UNION SELECT * FROM gallery2 WHERE topic_id="1493611" UNION SELECT * FROM gallery2 WHERE topic_id="170301" UNION SELECT * FROM gallery2 WHERE topic_id="1665216" UNION SELECT * FROM gallery2 WHERE topic_id="977922" UNION SELECT * FROM gallery2 WHERE topic_id="494322" UNION SELECT * FROM gallery2 WHERE topic_id="271653" UNION SELECT * FROM gallery2 WHERE topic_id="940951" UNION SELECT * FROM gallery2 WHERE topic_id="1035183" UNION SELECT * FROM gallery2 WHERE topic_id="1212906" UNION SELECT * FROM gallery2 WHERE topic_id="1756756" UNION SELECT * FROM gallery2 WHERE topic_id="305707" UNION SELECT * FROM gallery2 WHERE topic_id="1674292" UNION SELECT * FROM gallery2 WHERE topic_id="1146593" UNION SELECT * FROM gallery2 WHERE topic_id="161718" UNION SELECT * FROM gallery2 WHERE topic_id="204297"