#include<bits/stdc++.h>
using namespace std;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define ALL(A) A.begin(),A.end()
#define RALL(A) A.rbegin(),A.rend()
typedef long long LL;
typedef pair<LL,LL> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a,T b){return b?gcd(b,a%b):a;}
const LL mod=1000000007;
const LL LINF=1LL<<62;
const int INF=1<<30;
int dx[]={1,0,-1,0,-1,1,1,-1};
int dy[]={0,1,0,-1,-1,-1,1,1};




int main(){
    LL n,l;cin >> n >> l;
    LL nn = (n + l - 1) / l;
    LL ans = 1;
    LL M = 998244353;
    LL p = 2;
    while(nn){
        if(nn % 2){
            ans = ans * p%M;
        }
        p = p * p %M;
        nn /= 2;
    }
    cout << (ans + M - 1) % M << endl;
    return 0;
}