#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (int)(n); i ++)
#define irep(i,n) for (int i = (int)(n) - 1;i >= 0;--i)
using namespace std;
using ll = long long;
using PL = pair<ll,ll>;
using P = pair<int,int>;
constexpr int INF = 1000000000;
constexpr long long HINF = 100000'00000'00000'000;
constexpr long long MOD = 998244353;
constexpr double EPS = 1e-4;
constexpr double PI = 3.14159265358979;

long long modpow(long long N,long long K,long long mod = MOD) {
    long long ret = 1;
    while (K > 0) {
        if (K&1) {
            ret *= N;
            ret %= mod;
        }
        K >>= 1;
        N *= N;
        N %= mod;
    }
    return ret;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N,L; cin >> N >> L;
    ll x = (N + L - 1)/L;
    ll ans = (modpow(2LL,x,MOD) - 1 + MOD)%MOD;
    cout << ans << '\n';
    return 0;
}