#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 998244353;
constexpr bool debug = false;
//---------------------------------//

namespace tk {
template<typename T>
T mod_pow(T x, T n, const T & mod) {
	assert(mod > 0);
	assert(n >= 0);
	x = (x % mod + mod) % mod;
	T res = 1 % mod;
	while (n > 0) {
		if (n & 1) res = res * x % mod;
		x = x * x % mod;
		n >>= 1;
	}
	return res;
}
} // namespace tk


int main() {
	ll N, L;
	cin >> N >> L;
	ll c = (N + L - 1) / L;
	cout << (tk::mod_pow<ll>(2, c, MOD) - 1 + MOD) % MOD << endl;
}