This is the concerned [question][1]. The question has a negative score. So, it implies that the question is not valuable/worthy of being on the site [ I obviously disagree - moreover I got the answer too]. I don't like the negative score and would like to delete the question but if the question is valuable to the site then it shouldn't be negatively voted. [1]: http://cs.stackexchange.com/questions/45088/longest-simple-path-in-a-complete-graph