#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define eb emplace_back
const int MOD=998244353;
int n,m,w;map<int,int> mp;
struct Matrix {int a[3][3];Matrix() {memset(a,0,sizeof(a));}}I,a;
void W(int &x,ll y) {x=(x+y)%MOD;}
Matrix operator * (Matrix x,Matrix y)
{
    Matrix res;
    for(int i=0;i<3;++i) for(int j=0;j<3;++j) for(int k=0;k<3;++k)
        W(res.a[i][k],1ll*x.a[i][j]*y.a[j][k]);return res;
}
Matrix qpow(Matrix x,int y)
{
    Matrix res=I;
    for(;y;y/=2,x=x*x) if(y&1) res=res*x;return res;
}
int f(int x)
{
    if(x<0) return 0;if(!x) return 1;
    if(mp.count(x)) return mp[x];int res=0;
    if(!(x&1)) return mp[x]=(f(x/2)+f(x/2-1))%MOD;
    return mp[x]=1ll*f(x/2)*w%MOD;
}
int main()
{
    scanf("%d %d",&n,&m);
    a.a[0][1]=a.a[1][2]=a.a[1][0]=a.a[2][0]=1;
    for(int i=0;i<3;++i) I.a[i][i]=1;
    a=qpow(a,n);
    for(int i=0;i<3;++i) W(w,a.a[i][i]);
    printf("%d\n",f(m));return 0;
}