#include<iostream>
#include<cmath>
#define ll long long
#define mod 998244353

using namespace std;

ll modpow(ll a,ll b){
    ll ans = (ll)pow(a,b) % mod;
    return ans;
}

int main(){
    ll n,l;
    cin >> n >> l;
    ll pow = ceil((double)n/(double)l);
    ll ans = modpow(2,pow) - 1;
    ans %= mod;
    cout << ans << endl;
    return 0;
}