#include <bits/stdc++.h>
using namespace std;

// constexpr int MOD = 1000000007;
constexpr int MOD = 998244353;

long mpow(long a, long b) {
  long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % MOD;
    a = a * a % MOD;
    b >>= 1;
  }
  return res;
}

int main() {
  long N, L;
  cin >> N >> L;
  if (N <= L) return cout << 1 << "\n", 0;
  cout << mpow(2, (N + L - 1) / L) - 1 << "\n";
}