bool M1;
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define ull unsigned long long
#define LL __int128
#define db double
#define LD long double
#define Pii pair<int,int>
#define Pll pair<ll,ll>
#define Pull pair<ull,ull>
#define Pdb pair<db,db>
#define fir first
#define sec second
#define vec vector<int>
#define pb push_back
#define qlr cerr<<"qlr\n"
#define dyh cerr<<"dyh\n"
#define pc(x) __builtin_popcount(x)
#define uni(x,y) uniform_int_distribution<int>(x,y)(rng)
#define unl(x,y) uniform_int_distribution<ll>(x,y)(rng)
#define unr(x,y) uniform_real_distribution<double>(x,y)(rng)
#define F(i,a,b) for(int i=a,i##end=b;i<=i##end;i++)
#define UF(i,a,b) for(int i=a,i##end=b;i>=i##end;i--)
#define look_memory cerr<<'\n'<<abs(&M1-&M2)/1024.0/1024<<'\n'
#define look_time cerr<<'\n'<<clock()*1.0/CLOCKS_PER_SEC<<'\n'
mt19937 rng(time(0)^(*new int));
const ll INF=0x3f3f3f3f3f3f3f3f;
const int Mod=998244353;
template<typename T>
inline void inc(T &a,T b){
	if(b<0) b+=Mod;
	a+=b;
	if(a>=Mod) a-=Mod;
}
template<typename T>
inline void dec(T &a,T b){
	if(b<0) b+=Mod;
	a-=b;
	if(a<0) a+=Mod;
}
template<typename T>
inline void muc(T &a,T b){
	a=a*b%Mod;
}
template<typename T>
inline bool chkmin(T &a,T b){
	if(a<=b) return false;
	a=b;
	return true;
}
template<typename T>
inline bool chkmax(T &a,T b){
	if(a>=b) return false;
	a=b;
	return true;
}
int n,m;
ll cnt;
ll f[40][2];
struct Matrix{
	ll a[3][3];
	void init(){
		a[0][0]=0;
		a[0][1]=1;
		a[0][2]=1;
		a[1][0]=1;
		a[1][1]=0;
		a[1][2]=0;
		a[2][0]=0;
		a[2][1]=1;
		a[2][2]=0;
	}
	ll val(){
		return (a[0][0]+a[0][2]+a[1][0]+a[1][1]+a[2][1])%Mod;
	}
	void init0(){
		F(i,0,2) F(j,0,2) a[i][j]=0;
	}
	void init1(){
		init0();
		F(i,0,2) a[i][i]=1;
	}
};
Matrix operator*(Matrix a,Matrix b){
	Matrix c;
	c.init0();
	F(i,0,2){
		F(j,0,2){
			F(k,0,2){
				c.a[i][j]=(c.a[i][j]+a.a[i][k]*b.a[k][j])%Mod;
			}
		}
	}
	return c;
}
Matrix mt;
Matrix qpow(Matrix a,ll b){
	Matrix res,base=a;
	res.init1();
	while(b){
		if(b&1) res=res*base;
		base=base*base;
		b>>=1;
	}
	return res;
}
bool M2;
int main(){
	// freopen("yielding.in","r",stdin);
	// freopen("yielding.out","w",stdout);
	srand(time(0)^(*new int));
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m;
	mt.init();
	mt=qpow(mt,n-2);
	cnt=mt.val();
	f[0][0]=1;
	F(i,1,30){
		if(m>>i-1&1){
			f[i][0]=(f[i-1][0]*cnt+f[i-1][1])%Mod;
			f[i][1]=f[i-1][1];
		}
		else{
			f[i][0]=f[i-1][0];
			f[i][1]=(f[i-1][0]+f[i-1][1]*cnt)%Mod;
		}
	}
	f[30][0]=(f[30][0]%Mod+Mod)%Mod;
	cout<<f[30][0];
	look_memory;
	look_time;
	return 0;
}
/*
g++ A1.cpp -o A1 -std=c++14 -O2&&./A1

2 3
1 2
2 3
1 4
2 2
1 3
*/