#include <iostream>
using namespace std;
template <typename T>
T uPow(T z,T n, T mod){
  T ans = 1;
  while(n != 0){
    if(n%2){
      ans*=z;
      if(mod)ans%=mod;
    }
    n >>= 1;
    z*=z;
    if(mod)z%=mod;
  }
  return ans;
}
int main(){
    long long a,b;cin>>a>>b;
    long long c = (a+b-1)/b;
    cout << uPow(2LL,c,998244353LL)-1 << endl;
}