#include <bits/stdc++.h>
using namespace std;
#define rep2(i,m,n) for (int i = (m); i < (n); ++i)
#define rep(i,n) rep2(i,0,n)
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> P;
template<typename T> struct V : vector<T> { using vector<T>::vector; };
V() -> V<int>;
V(size_t) -> V<int>;
template<typename T> V(size_t, T) -> V<T>;
template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
const int INF = 1<<30;
const ll LINF = 1LL<<61;

const long long int MOD = 998244353;

long long int mpow(long long int x, long long int n)
{
    if(n == 0)
        return 1;

    long long int k = 1;
    while(n > 1)
    {
        if(n % 2 == 1)
        {
            k *= x;
            k %= MOD;
        }
        x *= x;
        x %= MOD;
        n /= 2;

    }
    return (k * x) % MOD;
}


int main()
{
    ll n, l;
    cin >> n >> l;
    n = (n + l - 1) / l;
    cout << (MOD + mpow(2, n) - 1) % MOD << endl;

    return 0;
}