#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)n; i++)
using ll = long long;
const ll mod = 998244353;

ll Pow(ll x, ll n){
  if(n == 0) return 1;
  if(n % 2 == 0) return Pow(x*x % mod,n/2);
  else return x * Pow(x,n-1) % mod;
}

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