#include <iostream>
#include <utility>
#include <vector>
#include <string>
#include <cstdio>
#include <cmath>


using namespace std;

int main(){

    long long int n,l;
    long long int s=998244353; 
    cin>>n>>l;
    
    n=(n+l-1)/l;

    long long int ans= pow(2,n)-1;


    cout<<ans%s<<endl;
    
}