#include <bits/stdc++.h>
using namespace std;

long long mod = 998244353;
//入力が必ず-mod<a<modの時.
struct mint{
    long long v = 0;
    mint(){} mint(int a){v = a<0?a+mod:a;} mint(long long a){v = a<0?a+mod:a;}
    mint(unsigned long long a){v = a;}
    long long val(){return v;}
    void modu(){v %= mod;}
 
    mint repeat2mint(const long long a,long long b){
        mint ret = 1,p = a;
        while(b){
            if(b&1) ret *= p;
            p *= p; b >>= 1;
        }
        return ret;
    };
 
    mint &operator=(const mint &b) = default;
    mint operator-() const {return mint(0)-(*this);}
    mint operator+(const mint b){return mint(v)+=b;}
    mint operator-(const mint b){return mint(v)-=b;}
    mint operator*(const mint b){return mint(v)*=b;}
    mint operator/(const mint b){return mint(v)/=b;}
 
    mint operator+=(const mint b){
        v += b.v; if(v >= mod) v -= mod;
        return *this;
    }
    mint operator-=(const mint b){
        v -= b.v; if(v < 0) v += mod; 
        return *this;
    }   
    mint operator*=(const mint b){v = v*b.v%mod; return *this;}
    mint operator/=(mint b){
        if(b == 0) assert(false);
        int left = mod-2;
        while(left){if(left&1) *this *= b; b *= b; left >>= 1;}
        return *this;
    }
 
    mint operator++(int){*this += 1; return *this;}
    mint operator--(int){*this -= 1; return *this;}
    bool operator==(const mint b){return v == b.v;}
    bool operator!=(const mint b){return v != b.v;}
    bool operator>(const mint b){return v > b.v;}
    bool operator>=(const mint b){return v >= b.v;}
    bool operator<(const mint b){return v < b.v;}
    bool operator<=(const mint b){return v <= b.v;}
 
    mint pow(const long long x){return repeat2mint(v,x);}
    mint inv(){return mint(1)/v;}
};

vector<vector<mint>> multima(vector<vector<mint>> &A,vector<vector<mint>> &B){
    int siza = A.size(),sizb = B.at(0).size();
    vector<vector<mint>> ret(siza,vector<mint>(sizb));
    for(int i=0; i<siza; i++) for(int k=0; k<sizb; k++){
        for(int l=0; l<A.at(i).size(); l++){
            ret.at(i).at(k) += A.at(i).at(l)*B.at(l).at(k);
            //ret.at(i).at(k) %= mod;
        }
    }
    return ret;
    //計算できる行列のみ.
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    long long N,K; cin >> N >> K;
    int Limit = K;
    vector<mint> fac(Limit+1,1),inv(Limit+1,1),facinv(Limit+1,1);
    for(int i=1; i<=Limit; i++) fac.at(i).v = fac.at(i-1).v*i %mod;
    for(int i=2; i<=Limit; i++) inv.at(i).v = mod-(mod/i*inv.at(mod%i).v %mod);
    for(int i=2; i<=Limit; i++) facinv.at(i).v = facinv.at(i-1).v*inv.at(i).v %mod;
    auto nCr = [&](int n, int r) -> mint {
        if(n < r || r < 0 || n < 0) return mint(0);
        return fac.at(n)*facinv.at(r)*facinv.at(n-r);
    };

    vector<vector<mint>> Z(K+2,vector<mint>(K+2)),A(K+2,vector<mint>(1));
    for(int i=0; i<=K; i++) for(int k=0; k<=K; k++) Z.at(i).at(k) = nCr(K-i,K-i-k);
    Z.at(K+1).at(0) = 1; Z.at(K+1).at(K+1) = 1; 
    A.at(0).at(0) = 1;
    while(N){
        if(N&1) A = multima(Z,A);
        Z = multima(Z,Z); N >>= 1;
    }
    cout << A.at(K+1).at(0).v << endl;
}