fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let n: Vec<u64> = s.split_whitespace().flat_map(str::parse).collect();
	let mut m = n[0] / n[1] + if n[0] % n[1] == 0 { 0 } else { 1 };
	let (mut a, mut r, d) = (1u64, 2u64, 998244353u64);
	while m > 0 {
		if m % 2 == 1 {
			a = a * r % d;
		}
		r = r * r % d;
		m /= 2;
	}
	println!("{}", (a + d - 1) % d)
}