const DIVISOR: u64 = 998244353;

fn power(base: u64, p: u64) -> u64 {
    if p == 0 { return 1; }
    if p == 1 { return base; }
    let temp = power(base, p / 2);
    temp % DIVISOR * temp % DIVISOR * power(base, p % 2) % DIVISOR
}

fn main() {
    let mut nl = String::new();
    std::io::stdin().read_line(&mut nl).ok();
    let nl: Vec<u64> = nl.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nl[0] / nl[1] + if nl[0] % nl[1] > 0 { 1 } else { 0 };

    println!("{}", (power(2, n) + DIVISOR - 1) % DIVISOR);
}