import java.util.*;
import java.lang.*;
import java.io.*;

public class Main {
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		// 入力
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		long L = sc.nextLong();
		long DIV = 998244353L;
		
		// 計算
		long disc = N / L;
		if(N % L != 0){
			disc++;
		}
		
		long ope = 1L;
		for(int i = 1; i <= disc; i++){
			ope = (ope * 2) % DIV;
		}
		ope--;
		
		// 出力
		System.out.println(ope);
	}
}