#include<bits/stdc++.h>

#define ll long long
#define pi pair<ll,ll>
#define vi vector<ll>
#define cpy(x,y,s) memcpy(x,y,sizeof(x[0])*(s))
#define mset(x,v,s) memset(x,v,sizeof(x[0])*(s))
#define all(x) begin(x),end(x)
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ary array
#define eb emplace_back
#define IL inline

using namespace std;

#define mod 998244353

ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0' || ch>'9')f=(ch=='-'?-1:f),ch=getchar();
    while(ch>='0' && ch<='9')x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    return x*f;
}
void write(ll x){
    if(x<0)x=-x,putchar('-');
    if(x/10)write(x/10);
    putchar(x%10+'0');
}

IL ll pls(ll x,ll y){return (x+y>=mod?x+y-mod:x+y);}
IL ll sub(ll x,ll y){return (x-y<0?x-y+mod:x-y);}
IL void Add(ll &x,ll y){x=pls(x,y);}
IL void Dec(ll &x,ll y){x=sub(x,y);}
IL ll mul(ll x,ll y){return x*1ll*y%mod;}

struct mat{
    ll a[6][6];
    mat(){memset(a,0,sizeof(a));}
    mat operator *(const mat &x){
        mat z;
        for(ll i=0;i<6;i++){
            for(ll j=0;j<6;j++){
                for(ll k=0;k<6;k++)Add(z.a[i][k],mul(a[i][j],x.a[j][k]));
            }
        }
        return z;
    }
};

mat trs,I;

ll f[33][2];

ll ask(ll x){
    if(x<=4)return I.a[x-1][0];
    mat z=trs,res=trs;ll y=x-5;
    while(y){
        if(y&1)res=z*res;
        z=z*z;y>>=1;
    }
    return (res*I).a[3][0];
}

int main(){
    #ifdef EAST_CLOUD
    freopen("a.in","r",stdin);
    //freopen("a.out","w",stdout);
    #endif

    ll n=read(),m=read();
    I.a[0][0]=1;I.a[1][0]=0;I.a[2][0]=1;I.a[3][0]=1;I.a[4][0]=1;I.a[5][0]=2;
    trs.a[0][1]=1;trs.a[1][2]=1;trs.a[2][3]=1;trs.a[3][4]=1;trs.a[4][5]=1;
    trs.a[5][0]=1;trs.a[5][1]=2;trs.a[5][2]=1;
    
    //cerr<<ask(5)<<' '<<ask(6)<<' '<<ask(7)<<' '<<ask(8)<<endl;

    ll coef=mul(2,ask(n-1))+mul(3,ask(n-2));
    if(m&1)f[0][0]=coef,f[0][1]=0;
    else f[0][0]=1,f[0][1]=1;
    for(ll i=1;i<=32;i++){
        if(m&(1ll<<i)){
            Add(f[i][0],mul(f[i-1][0],coef));Add(f[i][0],f[i-1][1]);
            Add(f[i][1],f[i-1][1]);
        }
        else{
            Add(f[i][0],f[i-1][0]);
            Add(f[i][1],mul(f[i-1][1],coef));Add(f[i][1],f[i-1][0]);
        }
    }
    write(f[32][0]);
    return 0;
}