002.rs: replace is in std::mem now
005.rs: use lcm in std::num
008.rs: use BufferedReader
011.rs: use BufferedReader
012.rs: replace is in std::mem now
013.rs: use BufferedReader and num crate
016.rs: use num crate
018.rs: max is in std::cmp now, use BufferedReader
020.rs: use num crate
022.rs: I/O handling
025.rs: replace is in std::mem now, use num crate