#include<stdio.h>
#include<map>
using namespace std;
/*
01 => 11, 10
10 => 01
11 => 10
*/
constexpr int mod=998244353;
struct Mat{
	int a[3][3];
	int *operator[](int i){return a[i];}
	const int *operator[](int i) const{return a[i];}
	Mat operator*(const Mat &x) const{
		return Mat{
			int((1ll*a[0][0]*x[0][0]+1ll*a[0][1]*x[1][0]+1ll*a[0][2]*x[2][0])%mod),
			int((1ll*a[0][0]*x[0][1]+1ll*a[0][1]*x[1][1]+1ll*a[0][2]*x[2][1])%mod),
			int((1ll*a[0][0]*x[0][2]+1ll*a[0][1]*x[1][2]+1ll*a[0][2]*x[2][2])%mod),
			int((1ll*a[1][0]*x[0][0]+1ll*a[1][1]*x[1][0]+1ll*a[1][2]*x[2][0])%mod),
			int((1ll*a[1][0]*x[0][1]+1ll*a[1][1]*x[1][1]+1ll*a[1][2]*x[2][1])%mod),
			int((1ll*a[1][0]*x[0][2]+1ll*a[1][1]*x[1][2]+1ll*a[1][2]*x[2][2])%mod),
			int((1ll*a[2][0]*x[0][0]+1ll*a[2][1]*x[1][0]+1ll*a[2][2]*x[2][0])%mod),
			int((1ll*a[2][0]*x[0][1]+1ll*a[2][1]*x[1][1]+1ll*a[2][2]*x[2][1])%mod),
			int((1ll*a[2][0]*x[0][2]+1ll*a[2][1]*x[1][2]+1ll*a[2][2]*x[2][2])%mod),
		};
	}
	Mat &operator*=(const Mat &x){return *this=*this*x;}
};
Mat pow(Mat x,int y){
	Mat r{1,0,0,0,1,0,0,0,1};
	for(;y;y>>=1,x*=x) if(y&1) r*=x;
	return r;
}
int n,m;
map<int,int> f;
int F(int x){
	auto it=f.find(x);
	if(it!=f.end()) return it->second;
	if(x&1) return f[x]=1ll*F(1)*F((x-1)/2)%mod;
	return f[x]=(F(x/2)+F(x/2-1))%mod;
}
int main(){
	// freopen("in.txt","r",stdin);
	scanf("%d%d",&n,&m);
	Mat r=pow(Mat{0,1,1,1,0,0,0,1,0},n);
	f[1]=((long long)r[0][0]+r[1][1]+r[2][2])%mod,f[0]=1;
	printf("%d",F(m));
}