#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int,int>;

const ll MOD = 998244353;

ll modpow(ll a, ll n, ll mod) {
  ll res = 1;
  while (n > 0) {
    if (n & 1) res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

int main() {
  ll n, l;
  cin >> n >> l;
  n = (n - 1) / l + 1;
  ll ans = modpow(2, n, MOD) - 1;
  if (ans < 0) ans += MOD;
  cout << ans << endl;
  return 0;
}