#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int main() {
  ll N, L;
  cin >> N >> L;
  N = (N + L - 1) / L;
  mint ans = mint(2).pow(N) - 1;
  cout << ans.val() << endl;
  return 0;
}