#include <bits/stdc++.h>
using namespace std;
#define modulo 998244353
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 2000000005
int beki(long long a,long long b,int M = modulo){
	int x = 1;
	while(b!=0){
		if(b&1){
			x=((long long)x*a)%M;
		}
		a=((long long)a*a)%M;
		b>>=1;
	}
	return x;
}

int main(){
	
	long long N,L;
	cin>>N>>L;
	
	N = (N+L-1)/L;
	
	int ans = beki(2,N);
	
	cout<<mod(ans-1)<<endl;
	
	return 0;
}