#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < n; i++)
using ll = long long;
using graph = vector<vector<int>>;

const ll mod = 998244353;
const int INF = 1001001001;

int main(){
    ll n, k; cin >> n >> k;
    ll ans = 1;
    if(n <= k){
        cout << ans << endl;
        return 0;
    }
    else{
        ll tmp = (n-1) / k;
        for(ll i = 0; i < tmp; i++){
            ans = (ans * 2 % mod + 1) % mod;
        }
        cout << ans << endl;
    }
}