#include <bits/stdc++.h>
using namespace std;
long long mod=998244353;
#define int long long
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
signed main(){
    long long N,L; cin>>N>>L;
    long long count=(N+L-1)/L;
    count%=mod;
    long long ans=1;
    vector<long long>A(30);
    A[0]=2;
    for(int i=1;i<30;i++){
        A[i]=A[i-1]*A[i-1];
        A[i]%=mod;
    }
    for(long long i=1;i<31;i++){
        if(count&(1<<i)){
            ans*=A[i-1];ans%=mod;
        }
    }
    ans--;
    cout<<ans<<endl;
}