import java.util.*;

public class Main {
    static final int MOD = 998244353;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long l = sc.nextLong();
        long count = (n + l - 1) / l;
        System.out.println((pow(2, count) - 1 + MOD) % MOD);
    }
    
    static long pow(long x, long y) {
        if (y == 0) {
            return 1;
        } else if (y % 2 == 0) {
            return pow(x * x % MOD, y / 2);
        } else {
            return pow(x, y - 1) * x % MOD;
        }
    }
}