#include <bits/stdc++.h>


using namespace std;
typedef long long ll;

#define REP(i,n) for(int i=0; i<int(n); i++)
#define FOR(i,m,n) for(int i=int(m); i<int(n); i++)
#define ALL(obj) (obj).begin(),(obj).end()
#define VI vector<int>
#define VP vector<pair<int,int>>
#define VPP vector<pair<int,pair<int,int>>>
#define VLL vector<long long>
#define VVI vector<vector<int>>
#define VVLL vector<vector<long long>>
#define VC vector<char>
#define VS vector<string>
#define VVC vector<vector<char>>
#define VB vector<bool>
#define VVB vector<vector<bool>>
#define fore(i,a) for(auto &i:a)
typedef pair <int, int> P;
template<typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }

const int  INF = 1 << 29;
const ll INFL = 1LL << 60;
const ll mod = 998244353;


ll pow_mod(ll n, ll k, ll m) {
	ll r = 1;
	for (; k > 0; k >>= 1) {
		if (k & 1)r = (r*n) % m;
		n = (n*n) % m;
	}
	return r;
}//nのk乗をmで割った時のあまり


int main(){
	cin.tie(0);
	ios::sync_with_stdio(0);

	ll n, m;
	cin >> n >> m;

	n = (n + 1) / m;

	ll ans = pow_mod(2, n, mod);
	ans = (ans + mod - 1) % mod;

	cout << ans << endl;

}