F-Fireworks(概率,三分) 题目描述 Kotori is practicing making fireworks for the upcoming hanabi taikai ^1^ . It takes her n minutes to make a single firework, and as she is not really proficient in making fireworks, each firework only has a probability of p×10−4p×10^{-4}p×10−4 to be perfect. After she finishe...