#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;
    int ans=1;
    for(int i=0;i<count;i++){
        ans*=2;
        ans%=mod;
    }
    ans--;
    cout<<ans<<endl;
}