#include "bits/stdc++.h"
using namespace std;
using ll=long long;
using ld=long double;
using vi=vector<int>;
using vvi=vector<vi>;
using vll=vector<ll>;
using vvll=vector<vll>;
using pii=pair<int,int>;
#define rep(i,n) for(int i=0;i<(n);i++)
#define sor(v) sort(v.begin(),v.end())
#define rev(v) reverse(v.begin(),v.end())
#define ALL(v) v.begin(),v.end()
#define pb push_back
template<class T>bool chmax(T &a, const T &b) {if (a<b) {a=b; return 1;} return 0;}
template<class T>bool chmin(T &a, const T &b) {if (b<a) {a=b; return 1;} return 0;}
template<class T>void printv(vector<T> v){ll n=v.size(); rep(i,n){cout<<v[i]; if(i==n-1)cout<<endl; else cout<<' ';}}
template<class T>void printvv(vector<vector<T>> v){for(auto V:v) printv(V);}
//constexpr int INF=1001001001;
//constexpr int mod=1e9+7;
constexpr int mod=998244353;

int main(){
    ll n,l; cin>>n>>l;
    n=(n+l-1)/l;
    ll res=1;
    ll x=2;
    while(n){
        if(n&1) (res*=x)%=mod;
        x=(x*x)%mod;
        n/=2;
    }
    res=(res+mod-1)%mod;
    cout<<res<<endl;
}