摘要：
Count the number of distinct sequences a1, a2, ..., an (1 ≤ ai) consisting of positive integers such that gcd(a1, a2, ..., an) = x and . As this numbe 阅读全文
摘要：
Lakhesh loves to make movies, so Nephren helps her run a cinema. We may call it No. 68 Cinema. However, one day, the No. 68 Cinema runs out of changes 阅读全文