#include<bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
#define vec vector<ll>
#define mat vector<vector<ll> >
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef complex<double> comp;
const ll inf=1e9+7;
const ll mod=998244353;
const int MAX=200010;

ll rui(ll a,ll b){
    ll res=1;
    ll x=a;
    while(b){
        if(b&1)res=res*x%mod;
        x=x*x%mod;
        b/=2;
    }
    return res;
}

signed main(){
    ll n,l;cin>>n>>l;
    ll k=(n-1)/l+1;
    ll ans=rui(2,k)-1;
    cout<<ans<<endl;
}