摘要：
Description Let's call the following process a transformation of a sequence of length nn . If the sequence is empty, the process ends. Otherwise, appe 阅读全文
摘要：
Description Student Andrey has been skipping physical education lessons for the whole term, and now he must somehow get a passing grade on this subjec 阅读全文
摘要：
Description Today an outstanding event is going to happen in the forest — hedgehog Filya will come to his old fried Sonya! Sonya is an owl and she sle 阅读全文