use std::io::*; use std::str::FromStr; #[allow(dead_code)] fn get_line() -> String { let stdin = stdin(); let mut line = String::new(); stdin.lock().read_line(&mut line).expect("io error."); line.trim().to_string() } #[allow(dead_code)] fn cast(s: &str) -> T { s.parse().ok().expect("parse error.") } #[allow(dead_code)] fn get_word() -> T { cast(&get_line()) } #[allow(dead_code)] fn get_vec() -> Vec { (&get_line()).split(' ').map(cast::).collect() } /* ---------- ここまでテンプレ ---------- */ fn main() { let mut w: u64 = get_word(); let d: u64 = get_word(); for i in (2..d+1).rev() { w -= w / (i * i); } println!("{}", w); }