#include<bits/stdc++.h>

#define INF 1e18
#define int long long
#define mod 998244353 

using namespace std;

inline int read(){
	int lre=0,f=1;
	char c=getchar();
	while(c<'0'||c>'9'){
		if(c=='-'){
			f=-1;
		}
		c=getchar();
	}
	while(c>='0'&&c<='9'){
		lre=(lre<<3)+(lre<<1)+(c-'0');
		c=getchar();
	}
	return lre*f;
} 

inline int quickpow(int a,int b){
	if(b==1){
		return a;
	}else if(b==0){
		return 1ll;
	}
	int half=quickpow(a,b/2);
	if(b&1){
		return ((((half*a)%mod)*half)%mod);
	}else{
		return (half*half)%mod;
	}
} 

struct matrix{
	int row,cow;
	int arr[10][10];
	void clear(){
		memset(arr,0,sizeof(arr));
	}
	void show(){
		for(int i=1;i<=row;i++){
			for(int j=1;j<=cow;j++){
				printf("%lld ",arr[i][j]);
			}
			putchar('\n');
		}
	}
}; 

matrix c;
matrix operator *(matrix a,matrix b){
	c.row=a.row;c.cow=b.cow;
	for(int i=1;i<=c.row;i++){
		for(int j=1;j<=c.cow;j++){
			c.arr[i][j]=0;
			for(int k=1;k<=a.cow;++k){
				c.arr[i][j]+=(a.arr[i][k]*b.arr[k][j])%mod;
				c.arr[i][j]%=mod; 
			}
		}
	}
	return c;
} 

matrix quickpow(matrix a,int b){
	if(b==1){
		return a;
	}
	matrix half=quickpow(a,b/2);
	if(b&1){
		return half*half*a;
	}else{
		return half*half;
	}
} 

int n,m;
map<int,int> mp;
matrix M;

int calc(int x){
//	cout<<"x="<<x<<endl;
	if(!x){
		return 1; 
	}else if(mp.count(x)){
	//	cout<<"U"<<endl;
		return mp[x];
	}
	if(x==1){
	//	cout<<"case 1"<<"!"<<endl;
		M.clear();M.row=M.cow=7;
		M.arr[3][6]=1;M.arr[4][7]=1;
		M.arr[6][3]=1;M.arr[6][4]=1;M.arr[7][6]=1;
		M=quickpow(M,n);
	//	M.show();
		mp[x]=(M.arr[3][3]+M.arr[4][4]+M.arr[6][6]+M.arr[7][7])%mod;
	}else{
	//	cout<<"down!"<<endl;
		if(x&1){
			mp[x]=(calc(x>>1)*calc(1))%mod;
		}else{
			mp[x]=(calc(x>>1)+calc((x>>1)-1))%mod;
		}
	}
//	cout<<"mp["<<x<<"]="<<mp[x]<<endl;
	return mp[x];
} 

signed main(){
	
	n=read();m=read();
	printf("%lld\n",calc(m));
	
	return 0;
}