/*
https://qoj.ac/problem/9479
*/
#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mpr make_pair
#define rep(i,n) for(int i=1;i<=n;i++)
#define repe(i,l,r) for(int i=l;i<=r;i++)
#define FOR(i,r,l) for(int i=r;i>=l;i--)
#define pii pair<int,int>
#define ALL(v) v.begin(),v.end()
using namespace std;
void chkmax(int& x,int y){x=x>y? x:y;}
void chkmin(int& x,int y){x=x>y? y:x;}
int n,m;
const int P=998244353;
unordered_map<int,int> ans;
struct Matrix{
	int a[3][3],n,m;
	Matrix(){
		memset(a,0,sizeof(a));
		n=m=0;
	}
}A,B;
Matrix operator*(Matrix a,Matrix b){
	Matrix c;
	c.n=a.n,c.m=b.m;
	for(int i=0;i<c.n;i++){
		for(int j=0;j<c.m;j++){
			c.a[i][j]=0;
			for(int k=0;k<a.m;k++){
				(c.a[i][j]+=1ll*a.a[i][k]*b.a[k][j]%P)%=P;
			}
		}
	}
	return c;
}
Matrix fast(Matrix a,int b){
	Matrix res;
	res.n=res.m=3;
	res.a[0][0]=res.a[1][1]=res.a[2][2]=1;
	while(b){
		if(b&1)res=res*a;
		b>>=1;
		a=a*a;
	}
	return res;
}
int dfs(int m){
	if(ans.find(m)!=ans.end())return ans[m];
	if(m&1)return ans[m]=1ll*dfs((m-1)/2)*dfs(1)%P;
	else return ans[m]=(dfs(m/2)+dfs(m/2-1))%P;
}
signed main(){
	scanf("%d %d",&n,&m);
	ans[0]=1;
	B.n=3,B.m=3;
	B.a[0][1]=1,B.a[2][1]=1,B.a[2][0]=1,B.a[1][2]=1;
	A.a[0][0]=A.a[0][1]=A.a[0][2]=1;
	/*
	11->10
	01->10
	01->11
	10->01
	
	11:0
	10:1
	01:2
	*/
	A.n=1,A.m=3;
	B=fast(B,n);
	for(int i=0;i<3;i++){
		ans[1]+=B.a[i][i];ans[1]%=P;
	}
	printf("%d\n",dfs(m));
	return 0;
}