#[allow(unused_imports)] use std::cmp; use std::fs::File; use std::io::Read; #[allow(dead_code)] fn pow_speedy_with_mod(mut p: i64, mut q: i64, m: i64) -> i64 { p %= m; let mut r = p; let mut ret: i64 = 1; while q > 0 { ret *= if q % 2 == 1 { r } else { 1 }; r *= r; r %= m; q /= 2; ret %= m; } return ret; } fn comb(n: usize, k: usize, m: i64, frac: &[i64], frac_inv: &[i64]) -> i64 { let mut ret = 1i64; if n < k { return 0; } ret *= frac[n] * frac_inv[n - k]; ret %= m; ret *= frac_inv[k]; ret %= m; ret } fn main() { let inputstatus = 0; let mut buf = String::new(); let filename = "inputrust.txt"; if inputstatus == 1 { let mut f = File::open(filename).expect("file not found"); f.read_to_string(&mut buf) .expect("something went wrong reading the file"); } else { std::io::stdin().read_to_string(&mut buf).unwrap(); } let mut iter = buf.split_whitespace(); let mut n: i64 = iter.next().unwrap().parse().unwrap(); let l: i64 = iter.next().unwrap().parse().unwrap(); n = (n + l - 1) / l; println!("{}", pow_speedy_with_mod(2, n, 998244353) - 1); // let n = iter.next().unwrap().parse().unwrap(); // println!("{}", n); // println!("{:?}", cum_num); }