In Detective Conan, 5+2=0 is one of the slogans of the dark group, which means "We don't leave anyone alive", that is, they will try their best to kill all those who may reveal the secrets of the organization, so that their whereabouts and existence are unknown, so as to achieve the goal of disappearing completely. 5 and 2 stand for English letters E and B respectively, and 0 stands for O. These three letters are abbreviated as "erasing black tissue". So 5+2=0 symbolizes the cruelty and ruthlessness of the dark organization.